Bull. nat. Hist. Mus. Lond. (Zool.) 67(2): 137—168 i, 
Xx (Bhoss a 

The genus I[schioscia Verhoeff, 1928 in 
Venezuela, with the description of six new 
species (Crustacea, Oniscidea, Philosciidae) 

ANDREAS LEISTIKOW 
Universitat Bielefeld, Abteilung fiir Zoomorphologie und Systematik, Morgenbreede 45, D-33615 Bielefeld, 
Germany and Ruhr-Universitat Bochum, Lehrstuhl fiir Spezielle Zoologie, UniversitdtsstraBpe 150, D-44780 
Bochum, Germany. e-mail: Leiste @ Biologie. Uni-Bielefeld.de 
Issued 29 November 2001 

CONTENTS 
MMO AICO cae seeasceces cou secs avbenctevasesseuaessequcuscePesaturccseutssasectstesssuvasadpositesesattrecsessoduevasssenstenes soasottacacseaeiactavsccen teeta ebecsttecsaesceteceootes 137 
Material spam@iIS(hOdS) inet teen. secteaeut satan cases coin ceaateuve tac seas Shc ouaasuss Seca et eeae ats aad cE up saa ca sec ace mesa oc O OUTS eee 137 
ISWSUCINLEA LLG Sir, cettatersvacnasteeccossctaeencedcacct rs tecotcer te rsssocrsuesece set: csuesscasanctsath oeeratneeceie stead inet acata ove duaubetas seausetseaier-alcesncttarsotane rievsesariveane 138 
USGRIOSGIARVGTIE ATA (DOUMIS HS OS) ie. c2..2.ceocessertecse sve vtttewcnuyrs sce Oeste ataach. SOedeter aa ce nace soe n dae bea detec een vt ce ade settee dice ron see cea u nes 138 
USGHIOSCIG FASCIUNONIS Spe TLOWE xe tertree atte acetate ae ee cena ee RSD SE Ue Bas ce Sas eae RS os od Meee Peak eran 138 
SCH OSCLGNIUTS ULC SPST OV a eau seseas ncuntts tev te tirces x amet es eUe eae tan csc c Mace aac as cal peers toes nat ana save ost guvSdees ies sen ooinvaceosUcoaassat ose 143 
USCHIOSCIA: COLON GLASP DOW: seta tetsr eta cc ate oats cette eee ae snc eS Bs RO Rs BOERS op SUITS Dia Sos RE Sass Selec 143 
WSGHIOSCIGN PUMICE? SP) AMON Bere ante ite es ee ca one sas rere tae oa coe = Seas Ins Sa vata lade eee nee Tee Sac is ash tetas eset: Saiseeaaeees 152 
US CRIOS CLAHSUGIN GASP) AT OMe tata scesst-cssesscvas caeie gsusanon sleet sstiaae st «acusdestaseveceaetotanenat canvenseszoecadsoie alsteviesrsSsiede idesasacuusexavacianaseazs 157 
ISG HIOSCLONUTECISGLGLGAS JS TLO Viper saes, ee a cts eee eae ease St one Base Seale cone nite Ce eae anand een ee be oh sc dautet ndavslstr Tees sosee ee eS 157 
VISCUSI OM pcre tank, tees ame ses. Seruce sete sna Mea tea ae tet sn'odstdeeMieexownvannacchaseueevemsensesceeaedte iva cueaiitvavaaasibigeeseluatiennskAeteeieds 166 
PS CRNOWIEAG CMMEMES Fass atetspen. Seaeaesaes es. saevss sttnontusctaeienod piweveevessaessausstseats Ged ccsgia ota autacieedechont vdaesatcakscsuncuehiuacaskestedetvackvascuseusleese 167 
PRE LE RCM CS Ba cacao te eae cerca maces gence etn sohb ok Seas cuswse d Rusu ghee sei caus Tava dee ter ah ovat aontrecs Ueagacv ch tsccestsasus cavGeeussessexauce 167 
SYNOPSIS. Terrestrial isopods (Oniscidea) collected in Venezuela in 1998 revealed plentiful material of the philosciid genus 
Ischioscia. This genus was, until very recently, represented in Venezuela by only a single species, /. variegata (Dollfus, 1893). 
The examination of the new samples lead to the description of six new species, all confined to small areas within Venezuela; five 
of which are closely related to /. variegata. These species are described in the present paper and the biogeography of the genus 
is discussed for Venezuela. The characters, which are important for reconstructing the phylogeny are presented and the 
relationships of the species are also discussed. 
INTRODUCTION 
The genus Ischioscia Verhoeff, 1928 was one of the first genera of 
philosciid Oniscidea described from South America (Verhoeff 1928). 
It was instituted for a species from Venezuela, I. lobifera Verhoeff, 
1928, which is now considered to be a junior synonym of J. 
variegata (Dollfus, 1893), a species reported from several localities 
in northern South America (Leistikow 1997). The genus comprises 
the largest species of terrestrial Isopoda in South America, with J. 
variegata reaching a body length of about 15 mm. Beside this 
species, several others are reported from the Peruvian and Brazilian 
Amazon region (Lemos de Castro 1955, Schmalfuss 1980), from 
Central America (van Name 1926, Arcangeli 1930, Leistikow 1997, 
1999 and 2000) and even from the lesser Antilles (van Name 1936). 
The total number of nominal species now is 16, and it is likely that 
several others will be found when the vast Amazonas region is better 
explored. The number of known species increased in those regions 
where larger collections were made. For example, in Costa Rica, ten 
species have been discovered in the last decade. The samples from 
Venezuela dealt with in this study revealed the presence of six more 
species; most of them close to /. variegata, but quite distinct in 
several characters. Hence, several records of I. variegata may show 
© The Natural History Museum, 2001 
to belong to other species. The species of /schioscia found in 
Venezuela are described in detail, the holotypes are deposited in The 
Natural History Museum, London for which the acronym BMNH is 
used below. Paratypes are deposited in The Natural History Mu- 
seum, London, the Muséum d’ Histoire Naturelle, Geneve (MHNG), 
Staatliches Museum fiir Naturkunde, Stuttgart (SMNS), the mu- 
seum of the University of Marcay, Venezuela (MUMYV), and in the 
collection of the author. The new species belong to the martinae- 
variegata-group of species distributed in Central America and 
northern South America. Particularly five of the new species are 
forming amonophylum together with /. variegata and I. panamensis. 
They seem to be restricted to smaller areas in Venezuela, and their 
distribution is compared with those of other taxa. 
MATERIALS AND METHODS 
Several samples of isopods preserved in 70% ethanol were examined. 
The samples were checked with a Wild stereoscope and in the case of 
new species a holotype was selected for preparation. Drawings were 
made using a camera lucida. Some specimens were dissected and the 
appendages were mounted on microscopic slides in glycerine gelatine, 
