Page 58 - Land Snails of New Mexico

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Range asbelongingtothisdistinct,endemic speciesand notto themorewidespreadD. laeve.He wrote:"D. heteruraoccurred . . . near the summit trail of the Black Range in the splendid forest at about 8 0 0 0 to 9 0 0 0 feet, f r o m S a w y e r P e a k to M o r g a n Creek,adistanceofover20milesasthecrowflies,andmuch m o r e a s t h e s n a i l - h u n t e r w a l k s . " H e a l s o r e c o r d e d it f r o m a l o n g WillowCreekintheMogollonMountains.
From study of the soft anatomy, Pilsbry (1944, 1948) concludedthatD.heterurawasarelictofanearlyinvasioninto North America of Krynickillus, a mainly Eurasian subgenus of Deroceras. He speculated that the subgenus Deroceras, to which D. laevebelongs,hadenteredNorthAmericaatalater t i m e a n d s u b s e q u e n t l y h a d s p r e a d f a r a n d w i d e . T h e r e h a s b e e n relativelylittleinterestintaxonomyandbiogeographyofthe family Limacidae in North America, perhaps because the fauna is not so diverse and salient as in the Old World. Thus, to our knowledge, further assessment of Pilsbry's views of D. heterura asaninterestingandratherancientrelicthasnotbeenmade.
Family Polygyridae
Limisa texasiana (S. Moricand, 1833, as Helix). Mémoires de la Société de Physique et d'Histoire Naturelle de Genève, 6:538, Pl. 1,Fig. 2. T.L.: Moricand gave the T.L. as "Mexique, dans le province de Texas." Pilsbry (1940:618) suggested that the type was likely from the vicinity of Brownsville, Texas. (Texas liptooth)
A recentsystematicrevisionofthePolygyridaebyEmberton (1995) allocates species traditionally placed in the large genus Polygyra among several genera. Consequently, the species long known asPolygyratexasianaisplacedinthegenusLinisa.
Pilsbry (1940) recognized two subspecies of L. texasiana as valid: the nominal subspecies and L. texasiana texasensis Pilsbry, 1902. He assigned western representatives of the c o m p l e x t o L . t. t e x a s e n s i s . H u b r i c h t ( 1 9 8 5 : 3 7 ) d i d n o t recognize the subspecies texasensis, and we follow him in referring specimens only to the species level.
GeneralDistribution—Thisisaspeciesofthesouth-central
UnitedStatesandnortheasternMéxico.Hubricht(1985:Map
373) mapped itas occurring livingfrom western Alabama to
Western Texas and from southernmost Kansas southward
throughmostofTexas.He indicateditspresentoccurrencein
western Texas as scattered, and he mapped a number offossil
occurrencesintheLlanoEstacadoandPecosRiverValleyof Texas.
N e w Mexico Distribution--We have found fossils of L.
texasiana at a number of localities in the Pecos River Valley, f r o m t h e R o s w e l l a r e a s o u t h w a r d . A p p a r e n t l y , it w a s a c o m m o n inhabitantofthevalleyinthepast.Hubrichtalsoindicateda fossil occurrence for L. texasiana in Chaves Co. (1985: M a p 373).Thisrecord,likethatofPilsbry(1940:620),ispresumably basedontherecordbyCockerell(1905:69)offossilmaterial from deposits along South Spring Creek near Roswell. In the P e c o s R i v e r V a l l e y , t h e r e i s a t l e a s t o n e p o p u l a t i o n o f L . t e x a s i a n a still l i v i n g , w h i c h w a s d i s c o v e r e d b y D r . D w i g h t W . Taylor in 1981 in Bitter Lake National Wildlife Refuge, east of
Roswell. Given theformer,more widespreadoccurrenceofthe speciesinthePecosValley,thepopulationatBitterLake Refuge appears to be relict.
H a b i t a t - - T h e habitat at Bitter L a k e R e f u g e is a low-lying, damp, seepage area along and near the Pecos Riverfloodplain. S u c h h a b i t a t s w e r e l i k e l y c o m m o n i n t h e l o w e r P e c o s V a l l e y i n New Mexico before agricultural development took place. SpecimensofL.texasianahavebeencollectedinurbanareasin CarlsbadandArtesia,New Mexico,andElPaso,Texas.
Genus Ashmunella
T h e n a m e A s h m u n e l l a is a p a t r o n y m h o n o r i n g T h e R e v e r e n d E. H. Ashmun, a 19th-century clergyman and amateur malacologist, w h o lived for a time in N e w Mexico. Reverend Ashmun was discussed above.
Bequaert and Miller (1973:19) have referred to Arizona as
"thelandofSonorella." Similarly,itseemsappropriatetorefer to N e w Mexico as the "land of Ashmunella." The center of
distribution for the genus, as mapped by Bequaert and Miller (1973:Fig. 5),liesapproximately along the southern Rio Grande Valley. The genus extends from north-central New Mexico southward intoChihuahua, México (southern extent not known), and from the Davis Mountains of West Texas westward to the HuachucaMountainsofsoutheasternArizona.
Because there is no significant information available about the phylogenetic position of species within the genus Ashmunella, we elect simply to list them by geographical regions, north to south and east to west, m u c h as Pilsbry did in his monograph of North American land Mollusca (1940). In most cases,knowing the geographic provenience of a specimen ofAshmunellawillreadilyallowonetoestablishitstaxonomic identity,because the majority of species are endemic to a single mountainrangeorcomplexofranges.
S p e c i e s o f N o r t h e r n N e w M e x i c o
Ashmunella thomsoniana (C. F. Ancey, 1887, as Helix). Conchologist'sExchange,2.64.T.L.:SantaFe Canyon, Santa Fe Co., New Mexico. (Sangre de Cristo woodlandsnail)
The earlytaxonomichistoryofthisspecies,thefirstland snail to be described from N e w Mexico, is discussed in the section, above, concerning early history of New Mexico
malacology.
The northernmostrepresentativesofthegenusAshmunella
consist of a pair of species: A. ashmuni on the west side of the R i o G r a n d e R i f t V a l l e y a n d A . t h o m s o n i a n a o n t h e e a s t s i d e .
ThezoologistT.D.A,Cockerell,who wasactiveintheLas Vegas area around the turn of the century, m a d e collections of A. thomsoniana and n a m e d several variants of the species. Pilsbry (1940:921-922) recognized two subspecies among living populations ofA. thomsoniana: the nominal subspecies, with its t y p e l o c a l i t y i n S a n t a F e C a n y o n , a n d A . t. p o r t e r a e ( P i l s b r y a n d C o c k e r e l l , 1 8 9 9 ) , w i t h t y p e l o c a l i t y i n S a p e l l o C a n y o n , a t 8 , 0 0 0
fton the eastern side of the Sangre de Cristo range. Pilsbry m a y
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