Table Of ContentMALACOLOGIA, 2000, 42(1-2): 39-62
PLUTONIA {CANARIVITRINA), NEW SUBGENUS, FROM THE CANARY ISLANDS,
AND THE PHYLOGENETIC RELATIONSHIPS OF THE SUBFAMILY PLUTONIINAE
(GASTROPODA: LIMACOIDEA: VITRINIDAE)*
Maria R. Alonso1 Manuel J. Valido1 Klaus Groh2 & Miguel Ibáñez1**
, ,
ABSTRACT
Plutonia(Canarivitrina), n. subgen.,andfournewspeciesofthissubgenusaredescribedfrom
three islands of the mid-Atlantic Canarian archipelago. The genus Plutonia Morelet, in Stabile,
1864 (of which Insulivithna Hesse, 1923, is a new synonym), restricted to the mid-Atlantic is-
lands, ischaracterizedbytheautapomorphyofthespecialcourseofthepenial retractormuscle,
roundingthe rightoptic nerve. Canarivitrina, n. subgen., hasa peniswithtwoeasilydistinguish-
ableportions:adistalone,shortandslightlywidened,containingaglobulartocylindricalandper-
forated penial papillalevelwiththeopeningofthevasdeferens(farfromthepenialapex), anda
proximal one, long and slender, with apical insertion ofthe penial retractormuscle andtwopar-
allel longitudinal innerstructures: atorus (thickfold, with roundish crosssection) and, opposite,
alaminarcrest(velum).Torusandpenialpapillaarecoatedbyglandulartissue,thepenialgland.
Theautapomorphiccharacterstateofthissubgenusistheproximalportionofthepenis, longand
equipped with internaltorusand velum.
Newdataaregivenaboutthesheaththatsurroundsthespoutoftheglándulaamatoria in Ca-
narivitrina, n. subgen., and in othersupraspecific Plutoniinae taxa demonstrating the homology
of the glándula amatoria and its spout sheath with the sarcobelum of the genus Semilimax, a
basal branch of the Vitrinidae: the subfamily Plutoniinae has the "sarcobelum" fused with the
proximal partofthevaginatoform the glándulaamatoria.
A phylogenetic scenario of the supraspecific taxa of the subfamily Plutoniinae is presented.
ThecladisticanalysisshowsthePlutoniinaeasthesistergroupofSemilimax,and Phenacolimax
asthe sistergroup ofthe remaining Plutoniinae: the genera Phenacolimax, Gallandia (which is
almostcertainlyajuniorsynonymofOligolimax), Arabivitrinaand Plutonia;butthisanalysisdoes
notresolvefortheothertaxabecausethedataarestilltoofewtoapplytoacladisticstudyofthe
group.
ThegenusPlutoniaincludesthesubgeneraPlutonia,s.str., Guerrina, Insulivitrina, Madeirovit-
rinaand Canarivitrina, n.subgen.ThepresenceofthisgenusinthearchipelagoesoftheAzores,
the Madeirasand the Canary Islands is probablyas old asthe humid "laurisilva" laurel-forest, a
Tertiary relict that colonized these archipelagoes before the impact of the Pleistocene glacia-
tions.
Keywords: Gastropoda, Vitrinidae, Plutoniinae, Canarivitrina, phylogeny, biogeography.
INTRODUCTION were described: G. christinae Groh, 1993; /.
eceroensisAlonso & Ibáñez, 1987; /. tubercu-
The Canarian Vitrinidae were studied only lata Ibáñez & Alonso, 1987; /. gomerensis
superficially between 1821-1954; eight spe- Alonso& Ibáñez, 1988; /. emmersoniMorales,
cies were described-one doubtful: Vitrina 1988; /. oromii Ibáñez & Alonso, 1988; /.
fasciolataA. Férussac, 1832; one of Guerrina machadoi Ibáñez & Alonso, 1990; /. nogalesi
Odhner, 1954: Helix cutícula Shuttleworth, Alonso & Ibáñez, 1990; /. tamaranensis
1852; and six grouped in Insulivitrina: Helico- Valido, 1990; and /. mascaensis Morales,
limaxlamarckiiA. Férussac, 1821; V blauneri 1987 (Alonso etal., 1987; Ibáñez etal., 1987;
Shuttleworth, 1852; V latebasis Mousson, Moralesetal., 1988;Validoetal., 1990, 1993).
1872; V canariensis Mousson, 1872; V retic- The last species, from Tenerife Island, has a
ulata Mousson, 1872; and V parryi Gude, peculiar penis, with a very long and slender
1896. In the last years, ten additional species proximalportionhavingaremarkabledistance
DepartmentofAnimal Biology, UniversityofLaLaguna, E-38206Tenerife,CanaryIslands, Spain
2MainzerStrasse25, D-55546Hackenheim,Germany
"NotesontheMalacofaunaoftheCanary Islands,38
"Towhomcorrespondenceshouldbeaddressed; [email protected]
39
40 ALONSO ETAL.
between the vas deferens entrance to the Abbreviations
penis and the insertion ofthe penial retractor.
We have recentlyfound fouradditional new a
species with the same penial characteristics:
threefrom LaGomeraandonefrom La Palma
(Fig. 5); these five species are assigned to a
new subgenus, Canarivitrina, n. subgen. In
this paper, we describe these taxa and at-
tempt a phylogenetic study of the entire sub-
family Plutoniinae.
METHODS
The introduction of Canarivitrina, n. sub-
gen., is the consequence of our anatomical
studies of the European Phenacolimax major
(A. Férussac, 1807), Arabivitrina jansseni
Neubert, 1988 (from the Asir province, Saudi
Arabia), Madeirovitrina nitida (Gould, 1848)
and M. marcida (Gould, 1848) from the
Madeira Archipelago, and the Canarian
species above mentioned. Moreover, biblio-
graphicdataonthe Plutoniinae have been ob-
tainedfrom Forcart(1959), Hubendick(1953),
Mermod (1930), Zilch (1979), and several ad-
ditional papers (Table 1).
Calculation of number of shell whorls fol-
lowsKerneyetal. (1979: 13).Theterms"shell"
and"specimen"intheenumerationsofthema-
terial studied refer to empty shells and live
specimens respectively, and "proximal" and
"distal" refer to the position in relation to the
gonad.Theterm"semislugs"referstotheclas-
sification of Tillier (1984), that is, the animal
usually cannot withdraw completely into the
shell, the posterior edge of the foot cavity is
lowerandfurtherforwardthanthemostposte-
riorpartofthedigestivetract, andthestomach
is retained in the uppervisceral cavity.
The cladistic analysis involves the eight
genus-group taxa of the Plutoniinae and was
performedusing PAUP4.0Beta2forWindows
(Swofford, 1999)andtheTreeviewapplication
(Page, 1996). Tree searches were performed
using the exhaustive search command. Zero-
legth brancheswerecollapsed, MulTreeswas
activated and the accelerated transformation
option (Ace Tran) was used. The characters
andcharacterstates used are listed inTable 2
andthedatamatrixinTable3mainlybasedon
the type species of the single supraspecific
taxa. Character polarity was determined by
outgroupcomparison using Semilimaxasout-
group for the reasons indicated in the com-
mentsafterthefamilydiagnosis.Allcharacters
haveequalweight. Twooutof ninecharacters
CANARIVITRINAAND THE PLUTONIINAE PHYLOGENY 41
TABLE 1. Genus-grouptaxa, type species and bibliographical sourcesofanatomical data.
Genus-grouptaxa Type species Sources
ArabivitrinaThiele, 1931 VitrinaarabicaThiele, 1910 Thiele, 1931; Forcart, 1957; Zilch,
1959; Neubert, 1998
Canarivitrina, n. subgen. P. (Canarivitrina) taburientensisn. this paper
sp.
OligolimaxFischer, in Paulucci, VitrinapaulucciaeFischer, in Manganelli etal., 1995
1878 Paulucci, 1878
Gallandia Bourguignat, 1880 Vitrinaconoidea, sensu Schileyko, 1986; Hausdorf, 1995,
(= TrochovitrinaO. Boettger, Bourguignat, 1880 [non and personal communication
1Í Martens, 1874] = Gallandia
o/ymp/caHausdorf, 1995
GuerrinaOdhner. 1954 HelixcutículaShuttleworth, 1852 Odhner, 1954; Ibáñezetal., 1987;
Validoetal., 1993; personal
unpublished data
InsulivitrinaHesse, 1923 HelicolimaxlamarckiiA. Hesse, 1923; Odhner, 1937;
Férussac, 1821 Forcart, 1957; Ibáñezetal.,
1987; Schileyko, 1986; personal
unpublished data
MadeirovithnaGroh & Hemmen, VitrinanitidaGould, 1848 Groh & Hemmen, 1986
1986
PhenacolimaxStabile, 1859 HelicolimaxmajorA. Férussac, Forçait, 1944, 1949, 1957;
1807 Hausdorf, personal communica-
tion; personal unpublished data
PlutoniaMorelet, in Stabile, 1864 ViquesneliaatlánticaMorelet, Wiktor& Backeljau, 1995; Mordan,
1860 personal communication
SemilimaxAgassiz, 1845 HelixsemilimaxJ. Férussac, Eckhardt, 1914; Forcart, 1944;
1802 Kerneyetal., 1979; Grossu,
1983; Schileyko, 1986; Hausdorf,
personal communication
(1,7) had three character states that were ing whorls. Protoconch generally spirally dot-
treated as nonadditive; character 1 was ted with numerous pits, which sometimes are
treatedas unordered, and7asorderedforthe also present on the teleoconch. Animal with
reasons indicated in the explanation of the penial gland and without penial nerve passing
cladistic analysis; four characters (3, 5, 8, 9) through the cerebral ganglion (see Hausdorf,
were autapomorphies with an additional au- 1998).
tapomorphy in each multi-state character.
Comments
RESULTS
Schileyko (1986) divided the Vitrinidae into
TAXONOMIC DESCRIPTIONS three subfamilies-Vitrininae Fitzinger, 1833;
Phenacolimacinae Schileyko, 1986; and
Family Vitrinidae Fitzinger, 1833 Semilimacinae Schileyko, 1986. Vitrina Dra-
Type genus: Vitrina parnaud, 1801, andCalidivitrina Pilsbry, 1919,
Draparnaud, 1801 were included in the subfamily Vitrininae (sar-
cobelum and glándula amatoria absent;
Diagnosis vaginaveryreduced). Semilimacinae, charac-
terized by the short vagina and by the pres-
Limacoidea, sensu stricto (semislugs and ence of a distinct, atrial sarcobelum, included
slugs with vas deferens running along the in- SemilimaxAgassiz, 1845, OligolimaxFischer,
side of the penial sheath; without sper- in Paulucci, 1878, Vitrinobrachium Kunkel,
matophore, epiphallus and flagellum), with 1929, and dubitatively Eucobresia Baker,
shell very thin, glossy, pale and translucent, 1929. This lastgenus lacksa sarcobelum and
usually with fewer than three rapidly expand- has a vaginal papilla nearthe atrium possibly
42 ALONSO ETAL.
TABLE 2. Characters used on the phylogenetic Odhner, 1954; Arabivitrina Thiele, 1931; In-
analysis.Thenumeration referstotheexplanations sulivitrina Hesse, 1923; Phenacolimax Sta-
inthetext. bile, 1859; Trochovitrina O. Boettger, 1880;
and Plutonia Morelet, in Stabile, 1864.
(1)IEEnxxStttheeeerrrlnnnlaaalll,,,rttehhdeeuaacnneiidmma=all2ccaannnwoittwhidtrhadwrianwtoinitto=it1= puhnyaHlcaectuiescpd,toatrbhflee(,S1e9m9it8hl)eimraeVcigitanrraidneeindpaaerthaipsbhyeslieyntsgitce,pmoalnayds-
(2)Teleoconch ornamentation only the Phenacolimacinae monophyletic.
Glossy = Moreover, the name Phenacolimacinae is a
Entirelyandverydensely ribbed = 1 junior synonym of Plutoniinae Cockerell
(3) Radulartype (1893), established for Plutonia.
Dichoglossan = According to Schileyko (1986), the Vitrini-
Beloglossan = 1 — nae and the Phenacolimacinae evolved inde-
(4) Location ofthe glándulaamatoria stimulator pendently from an unknown common ances-
organ
Distinctfrom vagina (Sarcobelum) = tor, while the Semilimacinae derived from the
Fused with the proximal partofvagina = 1 Phenacolimacinae by the transformation of
(5) Proximal portion of penis long, equippedwith the glándula amatoria ("vaginal gland") into a
torusand velum sarcobelum. We assume the contrasting the-
Absent = ory, sketched by Simroth (1889) and sup-
Present= 1 ported by Hausdorf (1997, 1998), is the most
(6) Penial sheath probable: the Phenacolimacinae derived from
Strong = a Semilimax-Uke ancestor by the fusion ofthe
Rudimentaryorabsent= 1 sarcobelum with the proximal vagina so as to
(7)FArrereaonfgtehmeenritghotfotphteicpenneiravler=etractormuscle give the glándula amatoria.
Passing roundingthe rightoptic nerve (Fig. 3G) The sarcobelum of the type species of
= 1 Semilimax (Fig. 1) consists of a voluminous
Penial retractorabsent =2 oblong oval or club-shaped stimulator not
(8) Vaginal retractormuscle covered by soft tissue, with a thick glandular
Absent= layer wrapping a longitudinal duct, which
Present= 1 opens distally intothe atrium through a spout,
(9) Oviducal retractormuscle the duct being upholstered (internally with re-
Absent=
spect to the glandular layer) by a thin layerof
Present= 1 circular muscles and a horny tube, the latter
missing in all the other Vitrinidae. The wall of
the distal portion of the sarcobelum invagi-
homologous to the spout of the sarcobelum nates sheathing the spout; atthe invagination
(Schileyko 1986: figs. 11,12). Phenacolimaci- edge, the sarcobelum wall is connected with
nae, characterized mainly by the long vagina the base of the spout by a very thin layer of
and the presence of a glándula amatoria connective tissue.
on the proximal vagina, includes Guerrina As Hausdorf (1998) has shown in his hypo-
TABLE 3. Originaldatamatrix usedforcladisticanalysis.Allcharacterswiththreecharacterstatesare
T
treated as nonadditive; thecharacter istreated as unordered and thecharacter'7'asordered. The
keysandnumeration refertotheexplanationsinthetext.Thevariableorunapplicablecharacterstates
werecoded asa '?'.
Key
CANARIVITRINAAND THE PLUTONIINAE PHYLOGENY 43
FIG. 1. Genital system of Semilimaxshowing the sarcobelum without the inner horny tube; redrawn from
Schileyko (1986: figs. 6-7) withoutscale, astheoriginal drawings.
thetical explanation of stimulator evolution in also possible: the sarcobelum could be origi-
the Stylommatophora, the genus Semilimax nated by the ancestral loss of portionsA and
2
may be seen as a basal branch of the Vit- A3, the shortening of the A4 portion (the
hrionmidoaleo,gtohuesattoriatlhesaperncioablealpupmenpdoissxiboflythbeeiOnrg- sppoorutti)o,n (aGnidusttih,epiernsv.agcionamtmi.o)n.oWfeA4aisnstoumtehetAhe1
thurethra, with portionsA3 and A4 absent and last theory because it explains favourably the
A2 and A5 fused. But another explanation is presence of the spout sheath.
44 ALONSO ETAL.
Subfamily Plutoniinae Taxa Belonging to Plutoniinae
Cockerell, 1893
Schileyko (1986: 147) referred Guerrina,
(junior synonym: Phenacolimacinae Schi- Arabivitrina, Insulivitrina, Phenacolimax, Tro-
leyko, 1986) chovitrina, and PlutoniaXo his Phenacolimaci-
Typegenus: PlutoniaMorelet, in Stabile, 1864 nae. Thetype species of Trochovitrina, T. led-
eri (O. Boettger, 1878) and Phenacolimax
annularis(Studer, 1820), studied bySchileyko
Diagnosis (1986) as examples ofthe respective genera,
were later grouped with Gallandia olympica
Vitrinidaewith athin shellvariable in shape, Hausdorf, 1995, in the genus Gallandia Bour-
normally with a narrow basal periostracal guignat, 1880, by Hausdorf (1995). Hausdorf
fringe. Distinct atrial stimulator (sarcobelum) recognized this genus to be characterized by
absent. Vagina long, its proximal portion the following autapomorphies: shell conoid-
housing a muscular glándula amatoria with a globose, shell and mantle lobes reduced, free
distal spout (see Schileyko, 1986). oviduct short, pedunculus [of the bursa copu-
The autapomorphic character state of this latrix] short and penis short.
subfamily isthe fusion ofthe sarcobelum with Ibáñez et al. (1987) grouped the taxa in-
the proximal vagina to givethe glándula ama- cluded by Forcart (1957) in Phenacolimax, s.
toria (Hausdorf, 1995). I. (Phenacolimax, s. str., Arabivitrina, Oligoli-
max, Insulivitrina, Plutonia, and Guerrina) and
Madeirovitrina in the Phenacolimacinae,
Comments mainlybasedonthesamecharactersasSchi-
leyko (1986).
The name Plutoniinae was established by The type species of Oligolimax, Vitrina
Cockerell (1893) for Viquesnelia atlántica paulucciae Fischer, in Paulucci, 1878, was
Morelet, 1860, an Azorean carnivorous slug considered by Forcart (1965) and Giusti
feeding on such animals as earthworms and (1971) to be a synonym of V. bonelliTargioni
slugs, and with an almost subterranean way Tozzetti, 1873, which belongs to the genus
of life, sheltered in moist places, in moss or Semilimacella Sobs, 1917, anatomically not
understones and detritus; dueto itsvery spe- far from Semilimax. Recently, Manganelli et
cializedfeaturesforapredatorylifestyle, Wik- al. (1995) indicated that V. paulucciaeis nota
tor & Backeljau (1995) proposed to remove it synonym of Semilimacella bonelliand that its
from the family Vitrinidae and assign it to a genital system anatomy is so similartothat of
separate family. the species grouped in Insulivitrina and Gal-
Cockerell (1893) mentioned the possibility landia, that these last two names could be
that Plutonia had also been used for a genus seen asjuniorsynonyms of Oligolimax.
of trilobites, and Collinge (in Cockerell, 1893) Gallandia is almost certainly a junior syn-
proposed an eventual change of the name onym of Oligolimax, butthecompletedescrip-
Plutoniinae to Vitriplutoniinae. However, as tion of O. paulucciae has not yet been pub-
Backhuys (1975) indicated, the name Pluto- lished (Giusti et al., in prep.). We therefore
nia for a genus of the Trilobita was published continueto utilize the name Gallandia. On the
later: Plutonia Hicks, 1871, Invalid Generic other hand, Insulivitrina is clearly distinguish-
Name by homonymy (ICZN, 1997, Opinion ablefrom Gallandia(and Oligolimax) because
1880). of the peculiar course of its penial retractor.
Shelley & Backeljau (1995) recognized a
case of homonymy between Plutoniinae Boll- Genus Plutonia Morelet, in Stabile, 1864
man, 1893 (Arthropoda, Chilopoda, type-
genus: Plutonium Cavanna, 1881) and Plu- Type species by monotypy: Viquesnelia at-
toniinae Cockerell, 1893, and proposed the lántica Morelet, 1860
emendation to Plutoniainae Cockerell, 1893. (Juniorsynonym: Insulivitrina Hesse, 1923,
However, Backeljau & Shelley (1996) modi- n. syn.)
fied their original application and proposed to
amend the myriapod name to Plutoniuminae Diagnosis
and to retain the molluscan name unchanged
as Plutoniinae; this proposition has been ac- Plutoniinaewiththeautapomorphiccharac-
cepted by the ICZN (1997, Opinion 1880). ter state "penial retractor muscle (starting
CANARIVITRINAANDTHE PLUTONIINAE PHYLOGENY 45
from the penis) moving forward, forming loop one of the Azorean "Insulivitrina" due to re-
around the optic nerve, passing below the duction of the penial retractor (see Com-
right ommatophore retractor, then running ments).
backwards (left of the same right om- Nervous system as described by Tillier
matophore retractor) to end on left side of di- (1989: 64) for the family. Palliai complex as
aphragm" (Fig. 3G). described by Wiktor & Backeljau (1995) in
Plutonia atlántica; lung small, kidney sig-
murethrous, bean-shaped, secondary ureter
Description closed like a tube, renal opening near anus
and pneumostome.
Slugs (Plutonia atlántica), semislugs (the Genital atrium, penis and distal vagina be-
"Insulivitrina group") or Vithna-Wke helicoid come completely evaginated when protruded
snails (the "Guerrina group"). Mantle border (in some preserved specimens and possibly
with well-developed mantle and shell lobes
also at mating; Fig. 2J). Genital atrium vari-
(the "Insulivitrina group"), with lobes small to able in length, connectedwith adjacentpartof
verysmall (the"Guerrinagroup"), orwith shell animal integument by short atrial muscles.
lobes absent {Plutonia atlántica, with a vesti- Penial complex without epiphallus and flagel-
gial shell entirely hidden in the mantle cavity). lum. Penial sheath thin, inconspicuous, rudi-
Right side of mantle generally with distinct mentary orabsent.
darker coloured "lateral band" above pneu- Bursa copulatrix duct and free oviduct in-
mostome. Footaulacopod. Soletripartite,with sert side by side at proximal end of glándula
distinct sole furrows, the lateral fused at short amatoria. Glandula amatoria variable in di-
dbiesnteaantchetfhreomshtealill,enbdo.rdFeoroetddborysaallpyaifrlaotftedniesd- omepnesnisontsh,rowuigdheratshpaonutd.istItalcvaangibneapianrtwihalilcyhtiot
tinct lateral crests extending forabout halfthe completelycoated byalayerofsofttissuethat
tail length; tail tip dorsally keeled. can easily be stripped off and it is formed by
Shell thin, greenish, translucent, glossy, thickoutermuscular layerand innerglandular
with 2-4 whorls. Shell variable in shape, from layerwrapping the longitudinal duct.
slightly depressed, keeled, conical above and Distal vagina variably long, its wall invagi-
with small aperture, to auricular with lower nated to envelop the spout of the glándula
asindde vweirthy lintatlrerdoewvepleorpieods,trvacearly lfarrigngee.apePrrtoutroe- samaamteorisap,outtotiipt.s Itnipvawgihnearteeditvafguisneasl wwailtlh atnhde
conch pitted, sometimes with radial ribs. spout wall entirely connected by thin connec-
Jaw oxygnathous, smooth, with median rib tive fibres easily removable without destroy-
and central denticle. Radula mainly di- ing the vaginal wall (allowing the invagination
choglossan (Jungbluth et al., 1985); central to be eliminated in the laboratory); at the in-
tooth little smaller than first lateral teeth, with vagination edge, the vaginal wall is also con-
long, slendermesocone having sharp pointed nected with the base of the spout by a very
tip and two basal ectocones reaching halfthe thin layerofconnectivetissue (asfound inthe
mesocone length; lateral teeth with long, wide sarcobelum of Semilimax; Fig. 1).
mesocone, onebasal ectoconeandonesmall
Spermoviduct long, about one-quarter of
laterodistal endocone; marginalteeth variable total genital system length. Prostate poorly
in shape. distinguishable. Albumen gland relatively
System of retractor muscles basically as small and oval in shape. Hermaphrodite duct
described by Odhner (1937) for Insulivitrina: long. Gonad follicular, located at apex of vis-
rightommatophore retractorfree of penis and
ceral sac.
vagina. Penial retractor, long and slender;
soon after it leaves the penis wall, it moves
forward passing below some nerves arising Comments
from the right pedal ganglion, then above the
nerve and the retractor of the lower right ten- The autapomorphic character state of the
tacle; soonafter, itformslooparoundtheoptic diagnosis was firstly evidenced in Plutonia
nerve and, passing below the right om- (Insulivitrina) lamarcki, two other Plutonia (In-
matophore retractor, moves backwards (leftof sulivitrina) species and Plutonia (Guerrina)
the same rightommatophore retractor) to end cutícula by Hoffmann (1929) and Odhner
on left of diaphragm. This situation is secun- (1937, 1954). It is shared by all the Canahan
daria lost in Plutonia atlántica and in at least and Madeiran Plutoniinae and was also evi-
46 ALONSO ETAL.
denced in the Azorean Plutoniinae (those erens into the same penis (farfrom the penial
which retain a penial retractor; Mordan, pers. apex). Penial papilla perforated, its central
comm.). It is interesting to note that one channel continuous with vas deferens. Penial
Azorean species (different from Plutonia at- papilla and torus coated by glandular tissue,
lántica) has been recently discovered to have the "penial gland". Distal portion of penis with
a very vestigial or perhaps missing retractor twoverythin penial folds, whichjoin level with
(Mordan & Frias Martins, in prep.), which the penial papilla, a small pit remaining be-
hence has been interpreted as a possible tween them and the papilla itself.Thin vaginal
synapomorphy of this species and P. at- fold sometimes present, ending before reach-
lántica. Thus, all the Macaronesian Plutoni- ing genital atrium.
inae would belong to the same genus, Pluto-
nia Morelet, in Stabile, 1864, of which Type Material
Insulivitrina Hesse, 1923, will become a sub-
genus. The relations of P. atlántica with the Holotype (Fig. 2A): collected by K. Groh
other Azorean Plutoniinae taxa is supported and M. Ibáñez (8-1-1988) in the Caldera de
by the cladistic analysis given below. Taburiente (La Palma Island; UTM:
The adult animal (with the exception of the 28RBS1879), at 750 m altitude; deposited in
Guerrina species), cannot withdraw com- AIT. Paratypes: 144 specimens and 22 shells
pletely into the shell. This may happen only collected between January 1988 and Febru-
after a long period of desiccation and (or) ary 1997, invarious localitiesofthe islandand
withoutfeeding, a situation that has been ver- deposited in ANSP (A 18852/2), CGH (32
ified in someprobablysenileadultspecimens. paratypes, 29 specimens and 3 shells), CRT
Forcart (1957) attributed a glandular func- (8 paratypes), CGS (1 paratype), SMF
tiontothesofttissuecoatingthe glándulaam- (311875/5), TFMC (MT 0314/2), ZMH
atoria. Other authors believe that despite it (2745/2) andAIT.
glandular appearance, it has a different func-
tion, as yet undetermined (Schileyko, 1986). Type Locality
The glandular function is feasible, but un-
proven since this tissue wraps the thick mus- Caldera de Taburiente, La Palma Island.
cularlayeroftheglándulaamatoriaexternally,
and there is no evident communication with Etymology
the central lumen of the glándula amatoria.
The Plutonia species are endemic to three The specific name refers to the Caldera de
mid-Atlantic archipelagoes located at the
Taburiente, a geological feature of La Palma.
western fringe of the Palaearctic: Azores,
Madeira and Canary Islands. The alpine Vit-
rina glacialis Forbes, 1837, once assigned to Habitat and Distribution
Insulivitrina(Forcart, 1944: 654), hasbeen re-
cently presumed as belonging to Eucobresia A species endemic to La Palma, occurring
Baker, 1929 (H. Nordsieck, in Falkner, 1991: in wide areas climatologically different, with
103); data on thecourse of its penial retractor pinewood and sometimes with lowland vege-
are nevertheless still pending. tmation, at an altitude between 300 and 1,800
(Fig. 5).
Plutonia taburientensis
Groh & Valido, n. sp. Animal
Diagnosis Body whitish-beige, with numerous small
pale-beige spots, more dense in number at
Plutonia with penis as long as vagina (in- head. Mantle and tail with darker grey spots
cluding its glándula amatoria portion), divided and a short blackish-grey lateral band. Foot
into two portions: proximal penis long, slen- sole sometimes with marginal grey spots.
der, with penial retractor muscle inserted at
apex and two internal parallel longitudinal Shell
structures, a torus and, opposite, a wide
velum. Distal penis short, slightly widened, Oblong, with about 2.5 whorls. Protoconch
containing a globular to cylindrical penial pitted; starting from beginning of second
papilla level with the entrance of the vas def- whorl, the pits are less deep and more scat-
FIG.2.A-D. Holotypeshells.A. P. taburientensis, n. sp. . P. ripkeni, n. sp. P. dianae, n. sp. D. P. falcifera,
n. sp. E. Protoconch of P. taburientensis, n. sp. F-G. Protoconch and pits detail of P. ripkeni, n. sp. H-l.
Radulaof P. ripkeni. n. sp. H, centraltoothand lateralteeth; I, marginalteeth. J.Aspecimen of P. mascaen-
siswiththedistal partofthegenitalsystemeverted, showingthepeniswiththe;penial papillaandtheva.gina
with the glándulaamatoria (bytransparency). Scale:A-D, J, 5 mm; E, F, 200 G, 100\ivn; H, I, 20
48 ALONSO ETAL.
FIGS. 3, 4. Genital system and anatomical details.A. P. taburientensis. n. sp., paratype; CalderadeTaburi-
.
ente. B. P. ripkeni, n. sp., paratype; Jerduñe. P. dianae, n. sp.. paratype; Montaña Bejira. D. P. falcifera.
n. sp., paratype;Tamolde. E. P. mascaensis(redrawnfrom Ibáñezetal., 1987, fig. 14). F. Internal penial de-
tailsofP. taburientensis,n. sp.G.ArrangementoftheInsulivitrinapenial retractormuscle.Scale:A-E, 1 mm;
F-G, withoutscale.
