452 FRANK COLLINS BAKER 



Sphaerium fabale Prime. One valve of this characteristic 

 species occurred with the other Sphaeria. It is evidently very rare. 



Pisidium virginicum (Gmelin). This large Pisidium is quite 

 common in this deposit and also quite typical. 



Pisidium compressum Prime. This is the most abundant 

 Pisidium in the Indiana deposit, as it often is in most recent and 

 fossil collections. The Indiana specimens are more typical than 

 those from the Ohio deposit. 



Pisidium cruciatum Sterki. A half-dozen valves, mostly 

 immature, occur in the material. 



Pisidium kirklandi Sterki. Fairly common but very charac- 

 teristic of the species as found living. 



Pisidium fallax Sterki. A half-dozen valves, small and slight, 

 are referred to this species by Dr. Sterki. 



Pisidium pauperculum Sterki. Two valves of a Pisidium are 

 identified with this species by Dr. Sterki. 



Pisidium noveboracense Prime. A score of odd valves, small 

 and largely immature, are referred to Prime's species by Dr. 

 Sterki. They are not typical of the species as found living today. 



Pisidium abditum Haldeman. Two valves are doubtfully 

 referred to abditum by Dr. Sterki. 



Valvatidae 



Valvata tricarinata (Say). Six young and immature specimens 

 of this carinate Valvata were found in the material. The spire is 

 rather depressed and the specimens somewhat resemble Valvata 

 bicarinata normalis Walker. 



Amnicolidae 



Amnicola limosa parva (Lea). A score or more specimens of 

 this variety of limosa occurred in the collection. The shells vary 

 from depressed to somewhat elongated. The whorls are all tumid 

 and strongly shouldered at the suture. The spire varies in height 

 and the aperture in rotundity. More than half of the shells are 

 immature. 



Amnicola walkeri Pilsbry. A single, large, typical specimen of 

 this Amnicola was found in the collection. It is larger than the 

 individuals of the same species from the Ohio deposit. 



