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 



Fig. 22 E u"r y s t o m i t e s k^llo; 

 (A3) Natural size 



■ i VVhilf. (sp.) Weathered natural section from^Valcour. 



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 



