Page 66 - Land Snails of New Mexico

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Distribution and Habitat--This is another of the southwestern New Mexico Ashmunellas with a restricted
distribution, known from only a few localities in the Florida Mountains. W e have taken it in a small elongate spill of limestone talus on the northwestern slope of Baldy Peak in the central and highest part of the Florida range. This likely m a y b e thetypelocalityindicatedbyFerriss(seeabove).We alsohave t a k e n it i n i g n e o u s r o c k t a l u s i n a n a r r o w c a n y o n o n t h e n o r t h side of SouthPeak, about 2 miles southwest of Baldy Peak. T h e species has not been found in the northern end of the Florida Mountains. ItappearsthattheFloridaMountainspresentlydo not offer m u c h suitable habitat for A. walkeri. This m a y also havebeenthecasewithOreohelixflorida,which,we suggest below, likely has become extinct in the range.
Ashmunella mearnsii (W. H. Dall, 1895, as Polygyra). ProceedingsoftheU.S.NationalMuseum 18:2.T.L.:The type was collectedby Dr. E. A. Mearns on his 1892 ascent of Hacheta Grande (=Big Hatchet Peak). Pilsbry (1915:329) suggested that the type locality was probably nearMearns' camp on a peak southeast of Hacheta Grande
(thispeak called "Daniels Peak" by Pilsbry--his collecting localityNumber 5).Inanyevent,theT.L.isnearoron Hacheta Grande. (Big Hatchet woodlandsnail)
Ashmunella hebardi H. A. Pilsbry and E. G. Vanatta, 1 9 2 3 . T h e N a u t i l u s , 3 6 : 1 1 9 . T . L . : n o r t h w e s t e r n s l o p e o f Big Hatchet Peak at about 7,600-ft elevation in a broad canyon, Hidalgo Co., New Mexico. (Hacheta Grande
woodlandsnail)
Distribution and Habitat--Ashmunella mearnsii seems to
bewidespreadintheBigHatchetMountaincomplex.We have taken it,living, at about 5,500-ft elevation as far south as a small mountain west of the northern end of the Alamo Hueco
Mountains(NE'%,sec.36,ofT32S,R16W).Anumberof living specimens were found on the north-facing slope of this small mountain north of the area of U-Bar Cave. Likely, it occurs in other, similar foothills of the southern Big Hatchet rangeinT32S,R 15W.Ithasbeentakenfromseveral localities in the higher, central part of the Big Hatchet range, where it occurs in both talus and thick leaf litter, especially b e l o w n o r t h - f a c i n g cliffs s u p p o r t i n g g o o d s t a n d s o f G a m b e l o a k . Also,wehavetakenitinlimestonetalusasfarnorthasthe n o r t h e a s t e r n s l o p e o f N o r t h H a t c h e t P e a k . I n a d d i t i o n , it o c c u r s as a fossil in: 1) Pleistocene sediments excavated by Dr. A. H. Harris in U-Bar Cave, mentioned above, and 2) hill-slope colluvial deposits on the north side of Howells Ridge in the Little Hatchet Mountains. It seems, then, that the Pleistocene rangeofthespecieswasrelativelyextensive,spreadingsome 30 milesfromtheU-BarCaveareatotheLittleHatchetMountains,
but, w e suppose, not continuously.
Ashmunella hebardi, on the other hand, appears to be a local
endemicoftheBigHatchetPeakarea.We havecollecteditnear what must be the type locality on the south side of Chainey Canyon (a broad canyon, as indicated in the description of the T.L.) on the northwestern, precipitous slope of Hacheta Grande. Here, it occurs under loose stones below cliffs in an area of unusually tallpinyon pines.
We donotknowhowfarA.hebardiextendstothewest
along the south side of Chainey Canyon. Collecting in the area for one day, w e moved to the east and upward along the cliffs, insofar as possible. Progressing eastward from an area where there were shells that appeared to be "good hebardi," w e first found shells that were intermediate between hebardi and
mearnsiiand,stillfartheralong,encounteredshellsthatseemed t o b e " g o o d m e a r n s i i . " A l l o f t h i s t r a n s i t i o n f r o m o n e s h e l l t y p e to another occurred within 0.3 mile and several hundred feet, altitudinally. It is not clear to us, at this time, whether A. mearnsii and A. hebardi should be regarded as intergrading subspecies or as hybridizingfull species.
Extremes ofthetwo taxaappear quitedistinct.Ashmunella hebardi shells differ from those of A. mearnsii in being larger, carinate rather than angular, having a dull, granular surface rather than the smooth, glossy surface of A. mearnsii, and having a thicker parietal callus, w h i c h is m o r e raised, marginally, f r o m the body whorl.
IntheBigHatchetMountains,we foundnofossilsthatwould elucidate problems about the relationship ofA. hebardi and A. mearnsii, but w e hardly have searched for them at this time. A few specimens found were judged likely to be fossils that had washedorfallendownfromcliffsonthenorthwesternfaceof
Hacheta Grande. Somewhat disconcertingly, these snails had greatly reduced dentition, suggesting the existence, at least in the p a s t , o f still a n o t h e r v a r i a n t i n t h e m e a r n s i i - h e b a r d i c o m p l e x !
Ashmunella animasensis J. Vagvolgyi, 1974.
Proceedings of the Biological Society of Washington, 87:153, Pl. 1,Fig. 8. T.L.: Animas Peak, Hidalgo Co., N e w Mexico. (Animas Peak woodlandsnail)
Distributionand Habitat-LikemostoftheAshmunellas
of southwestern N e w Mexico, this species is restricted to a single "montane island," the Animas Mountains. It has been takenaroundAnimasPeakonlyathigherelevations.We tooka n u m b e r of specimens in an extensive field of igneous talus o n the north side of Animas Peak at about 7,500-ft elevation. Vagvolgyi (1974:154) collected the species on the west side of t h e p e a k , n o t i n g t h a t t h e l o c a l i t y w a s ". . . s o m e w h a t b e l o w t h e summit,atanestimatedelevationof7,500-8,000ft.Pine,oak
and juniper grew in abundance on the slope, indicating a fair amount ofprecipitation."
Family Thysanophoridae Genus Thysanophora
Thysanophora hornii (W. M. Gabb, 1866, as Helix). American Journal of Conchology, 2:330, Pl. 21, Fig. 5. T.L.: In Arizona. According to Bequaert and Miller (1973:135): "T.L.: old Fort Grant, atjunction of Aravaipa (misspelled "Arivapa") Creek and San Pedro Riv, Pinal Co.,nowamarkedSite,8miNby5miW ofMammoth." (southwesternfringed-snail)
Distribution--The genus Thysanophora seems to be of Neotropical origin. Thysanophora hornii is widespread in México, including Baja California, and extends northward into
Texas,Arizona,andNewMexico.Wehavetakenitasfarnorth as Sierra Co. in N e w Mexico.