458 



NEW YORK STATE MUSEUM 



of one volution ; involution moderate, whorls embracing about 

 their hight. Umbilical aperture relatively large. 



Living chamber occupying three fourths of a volution. Aperture 

 not very well known but judging from the growth lines provided 



ig. 22 Eurystom ites kelloggl Whitf. (sp.) Weathered natural section fromValcour. 

 (A 3 ) Natural size 



with a deep hyponomic sinus [see pi. 18, fig. i] and expanding, 

 as indicated, by the periodical undulations and roughnesses of the 

 shell. Cameras shallow, attaining an average depth in the ephebic 

 part of the conch of 9 mm. Septa little concave, their concavity 



