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THE CHICAGO ACADEMY OF SCIENCES. 
Types: Academy of Natural Sciences, Philadelphia, two speci- 
mens (No. 58606). . 
Type Locarity: 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. 
CairorNIA: Antioch, Contra Costa Co. (Carlton); San Francisco Co. 
(Wood and Raymond). 
Orecon: Oregon (Nuttall). 
WASHINGTON: Upper valley of Nesqually River, near Ashford, Pierce Co. 
(O. D. Allen). 
GEOLOGICAL RANGE: Unknown. 
Ecotocy: Not recorded. 
RemMArRKS: 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 
cuthentic 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 appressed to the 
umbilical region, leaving a very small chink. It differs from truncatula 
in being almost imperforate 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 XX XI 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 
