1917. j natural sciences of philadelphia. 87 



The Cuchillo Range. 



This range is about six miles east of Chloride, the post office of 

 Fairview at the foot of the mountains. The peaks probably reach 

 up to 7,500 feet. 



On a brushy northern slope on the Thomas Scale trail, in the 

 southern end of the range, Oreohelix metcalfei cuchiUeusis and Holo- 

 spira cockereUi were found in abundance. The cover was scant, 

 and cattle plentiful. Both species were found again a couple of miles 

 further on, in Frank Calhoun's pasture. In both places they lived 

 in groves of oak, under limestone spawls and dead timber. 



At the north end of the range the peaks are higher, some having 

 large outcrops of fossiliferous limestone, but the only evidences of 

 living shells obtained were a few "bones" of Helicodiscus. In drift 

 debris, however, were many small shells which apparently graze on 

 the grassy slopes and meadows. 



The San Mateo Range. 



The San Mateo Range probably reaches a height of 8,000 feet. 

 The southern end is about 15 miles north of Monticello Post Office, 

 a village on the Canada Alamosa. The rock in this part of the range 

 is a friable, crumbling granite. Nearly the entire southern end is 

 a continuous slope of granitic fragments, many feet in depth. The 

 mesa continues nearl}^ to Monticello. Pinyon, juniper and low- 

 growing shrubs cover the hillsides. Along Chippy Creek, walnut, 

 quaking asp and yellow pine prevail. 



Around the edges of the rocky slides, Oreohelix cooperi and Ash- 

 munella were fairly abundant, but the smaller shells were scarce. 

 A day given to the peaks overlooking San Marcial, a couple of miles 

 farther, added only a few 0. cooperi to the collection. 



Characteristics of the Black Range Mollusk Fauna. 



The snail fauna of the Black Range is like that of the ]\Iogollon 

 Range in the rich development of Ashmunella, the species being also 

 related. Coarsely granulate species are a unique feature. It differs 

 from the ranges southward and westward by the absence of SonoreUa. 

 A special feature of the range is the Oreohelix metcalfei group, wonder- 

 fully varied in shape and sculpture. No doubt further members 

 of this group will be found in Sierra and Socorro Counties. Oreohelix 

 swopei also is special to the northern end of the Black Range, so far 

 as we know. 



The crest of the range everywhere has an abundant Canadian 



