Fossil Freshwater Mollusks from Oregon 



PABAPHOLYX PACKARDI, N. SP. 

 Plate 2, figures 1, 2, 3, 4, and 5 



Shell, large and robust, composed of about 3y 2 whorls which 

 increase rapidly; suture deeply impressed around the last whorl, 

 the depression almost amounting to a channel. Spire elevated but 

 apex flattened and smooth. The shell is otherwise coarsely sculp- 

 tured, the second whorl being marked with even ribs but these are 

 gradually obliterated toward the aperture. Aperture, auricular, 

 pointed below and thickened within; columella parallel with the 

 axis and bearing an obtuse tooth at its center. Umbilicus closed 

 by a deposit of callous material ; when this is broken away the per- 

 foration is found to vary from almost nothing to about two milli- 

 meters. 



MEASUREMENTS 



Diameter Altitude 



15.4 13.2 (Type) 



13.7 11.4 

 14.0 11.3 

 17.6 13.9 



19.5 ly.l 



17.8 15.5 



5.5 6.0 (Fresh shell from Locality 213) 



Type, No. 16 University of Oregon. Cast of same, No. 672, 

 Mus. California Acad. Sci. 



Type from University of Oregon locality 212. Warner Lake 

 Beds, eastern Oregon, Pliocene. 



This and Valvata oregonensis are the most abundant species 

 collected at locality 212. Large numbers of the shells are loosely 

 cemented into a mass which has very little admixture of foreign 

 material. Great variation is exhibited in the series studied, the 

 above description, with the exception of the last phrase, being 

 applicable to the type specimen only. It however represents the 

 most common variation. Some specimens are a little more bulbous 

 in the last whorl ; in some the ribbing continues to the aperture and 

 in some the ribbing is replaced by malleations. These variations 

 in sculpture have sometimes been attributed to saline waters. 



GENUS: CARINIFEX BINNEY 



CARINIFEX, SP. 



At locality 210 and possibly 212 there are fragmentary remains 

 of a species of the genus Carinifex which cannot be identified with 

 any known form. The species is characterized by its very narrow 

 umbilicus but it is not here given a name because none of the 

 specimens seems sufficiently well preserved to warrant this action. 

 Some specimens grew to huge size, almost two inches in diameter. 

 The species seems to be closer related to C. ponsoribii Smith, which 

 I believe to be restricted solely to Klamath Lake at present, than 

 any other but differs chiefly in having a much narrower umbilicus. 



[6] 



