SUBALPINE MOLLUSCA. 8l 



most authors, it seems almost certain that the three forms 

 nearest allied to S. triincatiiin are scarcely separable, as 

 species, from the Eurasian S . calyciilata Drap. 



Other calyculate species. — Six other forms of this 

 group are given by Prime, some having a little resem- 

 blance to S . rayinondi . S . clevatiim Hald. and S . sp/icr- 

 iciuii Anth. have the hinge margin even more curved, but 

 are more rounded and the first flatter. S . rosaceum 

 Prime, differs in smaller size, form nearly as in the Kla- 

 math shell (figs. 9, 10), but longer and less high, w^ith 

 reddish-brown epidermis, and nearly straight hinge, like 

 the other three. I have seen Californian specimens so 

 labeled, but of a pale color, perhaps immature examples 

 of S . 7'aymondi . 



A new species from the Uintah range in Wyoming, de- 

 scribed in 1886 as S . ttintahensis Call, from an elevation 

 of 10,500 feet in a snow-water lake, is nearly a perfect 

 globe. 



Iowa seems the most ptrolific of the States in this genus, 

 as twelve species are recorded by Prof. B. Shimek, six 

 of them calyculate, but no proofs are given of their au- 

 thenticity. 



S. cooler iaiinni Prime, n. sp., is given as a name only 

 in his last catalogue of Corbiculadas (Amer. Jour, of 

 Conch. VI, 1869). This was never described, because 

 the specimens I sent him were believed to be immature, 

 so small in fact that I supposed they were Pisidiums, but 

 he wrote that the ligament was on the longer side as in 

 Sphcprittin. They were from the little lake over 7,000 

 feet elevation in Johnson's Pass, south of Lake Tahoe. 

 It is probable that they were young of S . raynwudi, but 

 their present location being unknown, the locality must 

 be revisited to determine the species. 



From the preceding comparisons we conclude that the 



