Page 50 - Land Snails of New Mexico

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W e foundflourishingpopulationsofO. m. concentrica along Forest Road 523, where itcrosses both Silver Creek and RustlersCanyons,andwe alsofounditlivingatseveralplaces in the vicinity of the Royal John M i n e at the southern end of the Black Range.
Oreohelix metcalfei radiata H. A. Pilsbry and J. H. Ferriss, 1917. Proceedings of the Academy of Natural Sciences of Philadelphia, 69.97, Pl. 8, Figs. 2, 2a, 3,3c, 6, 6a; Pl. 9, Fig.11. T.L.: an outcrop of limestone on the east side of Spring Creek, where a small ravine enters from the east (Spring Creek is a southeastern tributary of Iron Creek) on the western slope of the Black Range, Grant Co.,New Mexico.
Distribution and Habitat--Oreohelix metcalfei radiata occurs along the canyons of Iron and Spring Creeks, the next complex north of the Silver Creek Canyon complex. It is probablymuch lesswidespreadthanconcentrica,althoughthe extent of its range to the north of Iron Creek Canyon is not known. W e have found it living along both Iron Creek and Spring Creek Canyons.
Oreohelix metcalfei metcalfei T. D. A. Cockerell, 1905. TheNautilus,18;113.T.L.:indicatedas"mountainsnear Kingston," Sierra Co., New Mexico. (Black Range mountainsnail)
The type of the nominal subspecies was collected by O. B. Metcalfe, w h o w a s associated with the agricultural college ( n o w New MexicoStateUniversity)atLasCruces,andwhodid considerable botanical and some incidental malacological collecting in the region in the early 1900s.
Distribution and Habitat--Living specimens of O. m. metcalfei have not been found in the immediate environs of Kingston, although fossils were found just to the east along Percha Creek Canyon. However, Oreohelix of the metcalfei complexareoftenfoundwheretherearelimestoneoutcrops,as occur to the southwest and northwest of Kingston. T h e T.L. is v a g u e , b u t it s e e m s r e a s o n a b l e t o v i e w t h e n o m i n a l s u b s p e c i e s asaninhabitantofthecanyonsoftheextensiveupperPercha Creeksystem,tothenorthandsouthofKingston.
OreohelixmetcalfeihermosensisH.A.PilsbryandJ.H. Ferriss, 1917. Proceedings ofthe Academy ofNatural SciencesofPhiladelphia,69;98,Pl.9,Figs 4-4b,12,T.L.: nearHermosainPalomasCreekCanyon,easternslopeof theBlackRange,SierraCo.,New Mexico.
Distribution and Habitat--We found O. m. hermosensis
still living in the vicinity of the T.L. in rock rubble along PalomasCreekCanyon,eastofthesiteoftheformervillageof Hermosa, in what had been an active mining district. Here, the canyon enters the foothills region of calcareous bedrock, the rocktypefavoredbythiscalciphilegroup.We foundHolospira cockerelli, discussed above, occurring with this Oreohelix.
W e have not seen any representatives of the O. metcalfei group from the upper canyons of Las Animas and Seco Creeks,
situated between canyons of the Percha and Palomas Creek systems.Perhapsinthesecanyons,whicharedifficultofaccess, thereareformsofthiscomplexthatareintergradationalbetween O. m. metcalfei to the south and O. m. hermosensis to the north.
O r e o h e l i x m e t c a l f e i c u c h i l l e n s i s H . A . P i l s b r y a n d J. H . Ferriss, 1917. Proceedings of the Academy of Natural Sciences of Philadelphia, 69.99, Pl. 9, Figs. 1-1b. T.L.: southernendoftheCuchilloMountains,SierraCo.,New
Mexico.
Distribution and Habitat-Despite the aridity of the
southern Cuchillo Mountains, specimens of O. m. cuchillensis werefoundinabundanceatthetimethatJ.H.Ferrisscollected
there in 1915, a lot of more than 200 specimens is mentioned (Pilsbry and Ferriss, 1917:99). W e made several attempts to search the southern Cuchillo range, but were unable to do so. Thus, we do not know the present status of this population, seemingly of small extent areally. W e found a few old, badly weatheredshellsofO.m.cuchillensisinthenorthernendofthe
CuchilloMountains.We alsofoundfossilsofthisspeciesin Pleistocene sediments in the northern Cuchillos, indicating that itis a relatively ancient occupant of the range.
Species of Oreohelix peripheral to the Black Range
In the accounts above, the Black Range and its eastern foothills have been proposed as being a center of evolution for membersoftheO.metcalfeicomplex. Metcalf(1974:99)and Crews and Metcalf (1982:262) proposed that, from such a center,therewasadispersalofmembersofthiscomplextoother mountainsoftheregion.Suchascenariohadalreadybeensetb y Pilsbry (1939:513) in recognizing the subspecies O. metcalfei
florida in mountains to the south of the Black Range.
In the following section, several species occurring in mountains peripheral to the Black Range are treated. Whether or not they may conform to a model of dispersal from a Black
Range center of origin remains to be tested.
Therewas apparentlydispersalofO.floridatoseveral
mountain ranges to the south and of O. caballoensis eastward to
t h e C a b a l l o M o u n t a i n s , w i t h s u b s e q u e n t e x t i n c t i o n o f t h e t a x a i n
these southern and eastern ranges. Dispersal was more
successful to the Pinos Altos Mountains to the west (O.
confragosa) and to the Magdalena Mountains and the area of the
San Agustin Plains to the north (O. magdalenae and O.
litoralis).(Note,however,reservationsindicatedunderaccount
ofO. magdalenae,below.)Metcalf(1974:99)andCrewsand
Metcalf(1982:262)notedthat,exceptforO. confragosa,all
these peripheral species have shell features that might be
considered as primitive within the O. metcalfei complex. A
general picture, then, m i g h t b e visualized in w h i c h there w a s a n
early dispersal to these peripheral areas of a fairly primitive
stageofO.metcalfei,ratherlikeexistingO. m.hermosensisand O. m. cuchillensis of the northeastern foothills of the Black
Range. Subsequently, as noted, the more primitive peripheral forms suffered extinctions related probably to climatic deterioration during the Holocene, but also in part, perhaps, to the natural extinction process to be expected on small islands. However, in the higher, more extensive, and more mesic