MOLLUSCA FROM INDIANA AND OHIO 451 



ANNOTATED LIST OF MOLLUSCA FROM SANDY LOAM DEPOSITS AT FLAT 

 ROCK RIVER, BARTHOLOMEW COUNTY, INDIANA. BELIEVED TO 

 BE REFERABLE TO THE SANGAMON INTERGLACIAL INTERVAL 



Unionidae 



Amhlema undulata (Barnes). Mr. Fluck reports this large 

 naiad as occurring in the deposit. 



Elliptio crassidens (Lamarck). A right valve 47 mm. in length 

 is quite characteristic of this heavy-shelled naiad, which is common 

 in the Ohio and Wabash rivers. 



Elliptio gibbosus (Barnes). Reported in the deposit by Mr. 

 Fluck. 



Actinonaias ellipsiformis (Conrad). A broken right valve and 

 two immature shells (right and left valves) somewhat broken are 

 referred to this common Indiana species. They are thinner, on 

 the average, than recent shells of this species. 



Carunculina glans (Lea). A left valve of a female shell 31 mm. 

 in length appears not to differ from recent shells in any important 

 degree. 



Lampsilis ventricosa (Barnes). This species is reported from 

 the deposit by Mr. Fluck. 



Species incerta cedis. 



A portion of the umbonal and lateral tooth region of an unknown 

 naiad also occurs in the material examined. It belongs to the 

 heavy-shelled species, like rubiginosus and undatus, but is quite 

 unidentifiable. 



Sphaeriidae 



Sphaerium solidulum (Prime). A number of valves of this 

 common species occur in the material examined, but they are not 

 very characteristic, many individuals varying considerably from 

 the typical form. The young and immature shells are much more 

 typical. 



Sphaerium stamineum (Conrad). Three valves of a Sphaerium 

 are referred to this species by Dr. Sterki, with doubt. 



Sphaerium striatinum (Lamarck). This species is about as 

 abundant in this deposit as solidulum. There are many different 

 forms, and the majority of the specimens are young or immature. 



