856 THE CHICAGO ACADEMY OP SCIEKl 



Types: Academy of Natural Sciences, Philadelphia, two speci- 

 men, | No. 58606). 



Type Locality : Oregon. 



Animal. Jaw. Radula and Genitalia: Unknown. 



Range (Figure 27) : Oregon, Washington and California. 



A species of the Columbian and Californian regions, occupying 

 the territory west of the Sierra Nevada range. It appears to be con- 

 fined to the Transition life zone. 



RECORDS. 



California: Antioch, Contra Costa Co. (Carlton); San Francisco Co. 

 (Wood and Raymond). 



Oregox : Oregon (Xuttall). 



Washington : Upper valley of Xesqually River, near Ashford, Pierce Co. 

 (O. D. Allen;. 



Geological Range : Unknown. 



Ecology: Not recorded. 



Remarks : Ferruginea has not been understood by students of 

 our fresh-water shells, and has been made a synonym of both humilis 

 and truncatula, principally for the reason that neither the types nor 

 authentic specimens have been examined. The two specimens figured 

 and described by Haldeman are preserved in the Academy of Natural 

 Sciences of Philadelphia and an examination of these shows that ferru- 

 ginea is a perfectly recognizable species, not closely related to either 

 of the species mentioned above, although apparently belonging to the 

 same group as humilis. The inner lip and columella are totally different 

 from those of humilis, being triangular and closely oppressed to the 

 umbilical region, leaving a very small chink. It differs from truncatula 

 in being almost wiperforaie and in having a slightly plicate columella. 

 The spire is regularly conic, the whorls scarcely disturbing a straight 

 line on either side drawn from apex to body whorl or aperture. The 

 sutures are much constricted, the whorls are flatly rounded and are 

 more or less strongly shouldered near the suture. The body whorl 

 is well rounded and in this respect resembles humilis. 



Haldeman's figures are very good, while Binney's figure is very 

 poor and was not correctly copied, being too much elongated. The 

 specimens figured on plate NNXI are similar to the types. Over fifty 

 specimens of this species have been examined and the characteristics 

 are very uniform, particularly the form of the columella. The shells 

 vary somewhat in width and in the height of the spire, and the aperture 

 varies correspondingly. The inward roll of the edge of the inner lip, 

 in some specimens, is very peculiar. Ferruginea will undoubtedly be 



