FLORIiDA -*="' MU,tUM L-ri. · OF NATURAL HISTORY™ SOME LANDSNAILS OF THE GENUS HUMBOLD TIA ATA FROM CHIHUAHUA AND WESTERN TEXAS Fred G. Thompson Vol. 46, No. 3, pp. 61-98 2006 UNIVERSITY OF FLORIDA GAINESVILLE The:FLORIDA MUSEUM OF:NATURAL, HISTOR¥is F16ritirs Biate·museuin' 6ftbalital histbs *dieated, to ufltler$tamdi~g,-Bfekrving;sand interpreting biological diversity'and ctil#fral»fitage. The BULLETIN OF THE FLORI-DA MUSEUM OFNATURAL HISTORY is.a pe¢r-reviewed publicafion that publishes the'results,~rof o_Iiginil,f#Sta-feh ib zoology; batany, pafieontdiogy, archaeology, and museum scfence. Address aft, inquiries to th© Managing Editvr of'the. Bulletin. Nimibets oftthe Bulletin 'afe published at iffegulaf intervals. Specffie volumes are not nedly completed M any one year. The end of a polu-me: Will be, noted atfihev foot * of the first page,ofthe last issue in that v.elu.mel Riclied *tanz; ·AYangging .Editor Cathleen, L. Bester, Production Bulletin C6mmittee Richard Franz, Chairperson .Ahn,Cordell Sarah Fa2enbaker RiehardtHulbert William,Mar4uardt Susan Milbrath Iryy R. Quitmyer Scott Robinson, Ex q#icio Member ISSN: 0071-6154 Publication Date:, September 30,2006 Sbrid cumiaddications *cunce~ning purchase or exchange of the iftililitatib-* Ellid ibdnuiclfipt quefies t6: M#naging'Editor ofthe ]311LETIN Florida Museum-ofNaturalr History Uni*ersity ofFlorida PO Ba 119]800 Gainesv,ille. FL326,114?80»US.A. Phone: 312.3924721 · - Kax: 352-846-0287 e-mail6 el#[email protected] SOME LANDSNAILS OF THE GENUS HUMBOLDTIANA FROM CHIHUAHUA AND WESTERN TEXAS Fred G Thompsoni ABSTRACT Humboldtiana. (Gastropoda, Pulmonata, Helicoidea, Humboldtianidae) is endemic to higher elevations of central and northern Mdxico, and southwestern Texas. The,fauna of the Mexican·State of Chihuahua is reviewed. Thirteen species are.recorded from there. This is estimated to be a ·small percent ofthe species that occur in Chihuahua. Humbo/dtiana presidii Pilsbry, 1939 from Texas is redescribed and is elevated to specific status. Formerly it was classified as a subspecies of H hogeana (Martens, 1892). New taxa are Gymnopallax n. subgen. for H. cicatricosa n. sp (referred species: H sylvania Thompson & Mejia, 2006);.Clydonacme n. subgen. for H. regula (referred·species: H. spectabile n. sp., H. titania n. sp., H. oberon n. sp., H. princeps n. sp. and H. hogeana Martens 1892); Aglotrochus n. subgen. for H. tanymastix n. sp. Humboldtiana balanites n. sp. and H corruga Thompson & Mejia, 2006 are referred tentatively to the subgenus Humboldtiana. The primary types of H. hogeana Martens, 1892; H. presidii Pilsbry, 1939, and H torrei Pilsbry 1935 are refigured. The subgeneric affinities of Humboldtiana torret Pilsbry, 1935 and H. eulatioe Metcalf, 1984 are uncertain. Key Words: M6xico, Chihuahua, Texas, terrestrial, snails, Gastropoda, Humboldtiana. TABLE OF CONTENTS Introduction 67 Methods and Terminology 67 Humboldliana 63 Humboldtiana presidii Pilsbry, \9'~9 64 Humboldtiana balanites new species 68 Humboldtiana corruga Thompson & Mijia, 2006 72 Subgenus GymnopaUax new subgenus 72 Humboldtiana cicatricosa new species 12 Homboldtiana sylvania Thompson & Mejia, 2006 75 Subgenus Clydonacme new subgenus 75 Humboldtiana reguld·new species 76 Humboldtiana spectabile new sperie~ 19 Homboldtiana titanic new species 82 Humboldtiana oberon new species 85 Humboldtiana princeps new sperie< Al Humboldtiana hogeana (Marlens, 1892) 90 Subgenus Aglotrochus'new subgenus ............ 92 Humboldiiana tanymastix new species 97 Undetermined subgenus 97 ' P.O. Box 117800, Florida Museum of Natural History, University of Florida, Gainesville, FL,32611-7800 USA [email protected]. Thompson , F.G. 2006. Some landsnails of the genus Humboldliana from Chihuahua and western Texas. Bull . Florida Mus . Nat. Hist. 46( 3 ):61 -98. 62 BULLETIN FLORIDA MUSEUM NATURAL HISTORY VOL. 46(3) Humboldtiana eulaliae Metcalf, 1984 91 Humboldttana torrei Pilsbry, 1935 97 Acknowledgmenk 97 Literature cited 97 INTRODUCTION made in 75 % ETOH with the aid of a Bausch & Lomb The,objective ofthis report is to review the landsnails of 0.7-3.0 sterio-microscope. the genus Humboldtiana in Chihuahua, and to clarify In the female reproductive system the dart-sacs the status of a single species from west Texas that was and dart-glands may be'reduced in size and one or more thought to be subspecifically related to a Mexican spe- dart-sacs may be absent in particular species. Two spe- cies. cies may have non-homologous but equal numbers of The genus Humboldtiana are a varied group of reduced dart-sacs. Thus, for comparative purposes each landsnails found over a large geographic area of west- ofthe dart-sacs is numbered (dsi, ds2' ds3' ds4) in a clock- ern Texas and M6xico. They tend to live in isolated wise sequence beginning with the dart-sac that faces colonies in rocky habitats, many of which are in arid the atrium and penis (see Fig. 10,60,76). The vas def- regions. They have received relatively little attention erens ascends along the vagina between ds, and ds,. because many of the rocky places in which they occur Abbreviations for other structures in figures of the re- are difficult to access, and seasonal weather conditions productive anatomy are as follow. agl albumen gland; influence the availability of live specimens. These fac- cae spermathecal caecum; atr genital atrium; db dart- tors, coupled with the historical paucity of systematic bulb; dgl dart gland; epi epiphallus; flg flagellum; pen malacologists, have yielded an understudied group of penis; pr penis retractor muscle; spt spermatheca; sptd organisrns. spermathecal duct; utr uterus; vagf free vagina; vag1 This report does not pretend to address adequately lower vagina; vagm middle vagina; vd vas deferens; vrg verge. Internally the penis bears a verge, which is an the taxonomy of Humboldtiana found in the study area. extension ofthe epiphallus into the penis chamben The Undoubtedly, only a small fraction of the species of internal structure of the penis and of the verge are im- Humboldtiana that live in Chihuahua are known. Chi- portant for discriminating species. huahua is the largest state in M6xico. Only a few weeks The vagina begins at the union with the penis at of field work have been devoted to landsnail surveys the genital atrium and extends upward to the point where there, and only a small fraction of the state has been the spermathecal duet branches from the uterus. The explored for mollusks. vagina consists of three segments, the lower vagina (vag),the middle vagina (vagm) and the free vagina METHODS AND TERMINOLOGY (vagf)· The lower vagina is separated from the middle Descriptions of new species are based primarily on the vagina by a ring of dart-sacs. The middle vagina is sepa- holotype. Meristic data as well as significant variations rated from the free vagina a ring of dart-glands. The pertaining to other specimens also are included in the relative length ofeach ofthe segments is taxonomically description. Morphological features among the paratypes 5ignificant (Burch & Thompson, 1956). that differ significantly from the holotype are indicated Species boundaries have become more clearly in parenthesis. defined than was apparent in an earlier study (Solem, The shell height (H) is the distance from the apex 1974). Shell characteristics of form, color pattern, em- to the basal lip parallel to the shell axis. The shell width bryonic sculpture and postembryonic sculpture consti- (W) is the greatest distance across the shell transverse tute valid criteria for species recognition. Anatomical to the shell axis. The aperture height (AH) is measured feature, including color patterns and numerous aspects from the basal lip to the point of attachment ofthe upper of the reproductive anatomy are useful also for species lip. The aperture width (AW) is measured from the definitions. Both shell and anatomical features provide edge of the outer lip to the inner edge of the columellar bases for showing relationships. lip transverse to the shell axis. Averages (Avg) and stan- Museum acronyms used in this paper are as fol- dard deviations (SD) include measurements ofthe holo- lows: type as well as paratypes. ANSP - Academy of Natufal Sciences, Philadel- Specimens were relaxed in the field with a weak phia, PA. chloral hydrate solution, fixed for 24 hours in 85% ETOH BMNH - British Museum (Natural History), Lon- and then preserved in 75% ETOH. Dissections were don. THOMPSON: Humboldtiana from Chihuahua and Texas 63 ITCV - Instituto Tecnologico de Ciudad Victoria, genus. The subgenera are separated by differences of Tamaulipas, Mexico. the shell and of the reproductive anatomy. UF - Florida Museum ofNatural History, Univer- sity ofFlorida, Gainesville, FL. Key to the subgenera of Humboldtiana. USNM - National Museum of Natural History, Washington, D.C. 1 a. Dart-glands absent. Dart-sacs absent. Penis with- out a verge. Vagina undifferentiated into lower, middle Genus Humboldtiana Von Ihering, 1892 and upper segments. ................................... ........................Oreadne Thompson & Brewer, 2000. The genus Humboldtiana is in a state of system- atic flux. This is, in part, because· the genus is very Other characters. Shell without granular sculpture. widely distributed through central and northern M6xico Embryonic whorls smooth. Shell shape depressed- and southwestern Texas. Throughout this range the helicoid. Color pattern banded. Mantle color-pattern genus has undergone extensive evolution in shell char- uniform. Penis retractor muscle inserting