456 FRANK COLLINS BAKER 



Vitrea hammonis (Strom.). Two typical specimens of this 

 species were found in the sand from the interior whorls of a specimen 

 of Pyramidula solitaria. This small land mollusk, as well as the 

 other speciesof this family, appears to be very rare. 



Circinariidae 



Circinaria concava (Say). Not uncommon and as large as the 

 recent shells from Indiana. The aperture is rounder in the fossil 

 shells than in the recent individuals, and the peculiar flattening 

 of the upper part of the outer lip is rarer in the fossil specimens. 



Helicidae 



Polygyra tridentata (Say) . Polygyrafraudulenta'Pihhry. These 

 two common species are apparently not abundant in the deposit in 

 question. 



Polygyra inflecta (Say). As but two individuals of this species 

 were found in the large quantity of material examined it must be 

 rare among the fossil land shells of this part of Indiana. The 

 shells are apparently normal in both size (12 mm.) and form. 



Polygyra profunda alba Walker. Nearly all of the specimens 

 referred to profunda belong to the variety alba. One individual 

 occurred which has the usual narrow bands on the last whorl and in 

 addition has several large rosy blotches of color on the last half of 

 the body whorl. 



Polygyra zaleta (Binney) = exoleta (Binney). Zaleta is appar- 

 ently rather rare, only seven specimens being found among several 

 hundred land shells in the material. One specimen has a well- 

 marked parietal tooth; the others are toothless. 



Polygyra elevata (Say). Next to Pyramidula solitaria, elevata 

 is the most abundant land mollusk in the deposit. In size and form 

 they do not differ from the recent individuals. The same variation 

 in height of spire noted among recent shells is also present in the 

 fossil form. 



Polygyra thyroides (Say). Of the twelve specimens of this 

 species examined, three have a well-marked tooth on the parietal 

 wall; the others are toothless. There is some variation in size, 

 the extremes being 22 and 28 mm. in greatest diameter. 



