Page 33 - Land Snails of New Mexico

ft and 7,150-ft elevations, respectively. In Zuñi Canyon, specimens were found on a north-facing slope of a reentrant of the canyon. The slope was strewnheavily with basaltic talus, and shellsweretakenfromdeepleaflitter,mainlyofGambelOak leaves.Thelocalitiesarearid--incontrasttothehighermontane meadows at Ojo Redondo in the Zuñi Mountains, where P. hebes has been collected. The specimens collected in the Zuñi Mountains are the only ones taken in our survey. They are in the size range considered "very long" by Pilsbry (1948:940), the largestreachingaheightof4.2mm withca.10whorls.It appears that P. syngenes is a species more widespread in Arizona, which extends only into the west-central part of N e w Mexico.
Pupilla sonorana (V. Sterki, 1899, as Pupa). The Nautilus, 12:128. T.L.: Whiteoaks, Lincoln Co., New Mexico. (three-toothcolumn)
GeneralandNew MexicoDistribution--Pupillasonorana is a quintessential N e w Mexican pupillid, as most records are from this state. Itoccurs in southern mountains, west to east: Big Hatchet, Organ, San Andres, Oscura, Jicarilla, Carrizo, Capitan, Sacramento, and Guadalupe Mountains. The above distribution suggests that it evolved in the mountains surrounding the Tularosa Basin. The species occurs (living) in the Guadalupe Mountains of Texas and as a fossil in the Sierra Diablo and FranklinMountainsofTexas.
Habitat—Pupillasonoranaistheonlymemberofitsgenus intheBig Hatchet, Organ, San Andres, and JicarillaMountains, w h e r e it o c c u r s f r o m t h e U p p e r S o n o r a n Z o n e t o t h e m o u n t a i n tops. In the Oscura Mountains and in the higher mountains east of the Tularosa Basin, itoccurs with P. blandi mainly in forested habitatsoftheTransitionandCanadianLifeZones. Specimens ( U M M Z 109934 and 109936) from the localities listed by Pilsbry (1948,929) from San Miguel and Mora counties do not seemtobeP.sonorana.
Remarks--In the Sacramento, Capitan, and Carrizo Mountains, where P. sonorana and P. blandi occur together, their shells are separated rather easily (see key, above). The smaller size and crescentic parietal tooth of P. sonorana are distinctive. Itseems necessary to emphasize that P. sonorana andP.blandiarequitedistinctspeciesandshownoevidenceof intergradation, inasmuch as Bequaert and Miller (1973:50) and Fullington (1979:106) suggested that they might be conspecific. FullingtonreportedP.blandifromtheGuadalupeMountainsof Texas,butwehavenotobserveditinourcollectionsfromthat range in either N e w Mexico or Texas, except as a fossil in Pleistocenehillslopecolluvialdeposits.
Some shells in one lot of P. sonorana observed exhibit
whorls that increase in width, dorsally, as in P. syngenes, but shells have the denticulation of P. sonorana, and are much
smaller than shells of P. syngenes.
Genus Pupoides
Pupoides albilabris (C. B. Adams, 1841, as Pupa). A m e r i c a n J o u r n a l o f S c i e n c e , 4 0 : 2 7 l. N o p r e c i s e T . L . (white-lip dagger)
General Distribution--Pilsbry noted (1948:923) that P. albilabris"occursinallthestatesfromArizonaandColorado
eastward, but never at high elevations."
New Mexico Distribution and Habitat—Pupoides
albilabrisiswidespreadinsouthernandeasternNew Mexico,
butitisprobablyunderrepresentedincollectionsbecauseofthe
lackofcollectingatlower elevations. Pupoides albilabris isone of the few native N e w Mexico land snails that are tolerant of
conditions of the Lower Sonoran Life Zone. In the eastern and
southernpartsofthestate,italsoextendsintotheUpper SonoranZone foothills,butisnotfoundatelevationsabovethe
Upper Sonoran Zone. Pupoides albilabris may be found in brushyareasunderstonesorinleaflitter.Inthesouthernpartof the state, itmay occur under stems of dead yuccas and dead, detached caudices of sotol (Dasylirion).
Pupoides hordaceus (W. M. Gabb, 1866, as Pupa.) American Journal of Conchology, 2:331. T.L.: Fort Grant, atthejunctionoftheSan Pedro River and Aravaipa Creek, Pinal Co., Arizona. (ribbed dagger)
Pupoides hordaceus and P. inornatus (below) are columnar in shape and have regularly spaced riblets, which are less developed in P. inornatus. Shells of P. hordaceus are slightly more slender than those of P. inornatus, and its aperture is smaller in relation to the rest of the shell. The differences are slight, and it is possible that the two taxa are conspecific and should be treated only as subspecies (in which case, P. hordaceus, having priority, would become the specific name). Clear evidence for intergradation is not available. Pilsbry (1948:925-926) allocated specimens from near Las Vegas to both P. hordaceus and P. inornatus. Itispossible thatthey were
drift or fossil shells of different proveniences. Since shells attributable to the two species occur already in the Pleistocene, thisarguesforretainingthem asseparate,fullspecies.
In our collections, we have found P. hordaceus to be a c o m m o n fossil in Pleistocene sediments from the eastern
foothillsofthe Guadalupe Mountains westward to southwestern New Mexico. The species is especially characteristic of Pleistocene deposits of the Rio Grande Valley, from D o ñ a A n a Co. northward to Rio Arriba Co.
General Distribution--This species (or subspecies) is
probably restrictedto Arizona, western Colorado, N e w Mexico, and Utah.
New Mexico Distribution--InNew Mexico,P.hordaceus maybecharacterizedasasnailoftheUpperSonoranZone, rangingfromthecentralNew Mexicohighlandsnorthwestward.
Habitat—This species has been taken both in broken country and in areas of low gradient in pinyon-juniper woodlands of the Upper Sonoran Life Zone. All localities are in relatively xeric habitats. At Echo Amphitheater, Rio Arriba Co., living specimens were found under dead juniper branches. In other places, they were taken in collections of leaflitterfrom brushy habitats. Some of our specimens of P. hordaceus are shells takenfrom anthillsofPogonomyrmex sp.
Pupoides inornatus E. G. Vanatta, 1915. The Nautilus, 29:95, T.L.: Drift of White River, Washington (now Shannon) Co., South Dakota. (Rocky Mountain dagger)
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