338 NEW YORK STATE MUSEUM 



its distance from the suture ; thence it recurves more gradually. Surface 

 bearing only very tine concentric growth lines which may be almost obso- 

 lete on the later parts of the shell. 



Dimensions. But a single example of this characteristic shell has been 

 seen. This has a hight of 7 mm and a diameter across the body whorl of 

 9 mm. 



This shell may in form and proportions well be compared with 

 Natica adorfensis Holzapfel 1 which is a similarly rotund shell, 

 though larger and with slightly more elevated spire. 



Habitat. Genesee province ; Chautauqua subprovince. In the soft 

 shales on Big Sister creek, Angola, Erie co. 



Diaphorostoma pugnus sp. nov. 



Plate 19, fig. 15, ift 



Shell of fairly large size, having the general aspect of the well known 

 Hamilton species I). lineatum Conrad. Volutions 3, rapidly expanding, 

 spire depressed, suture not deeply impressed. Final whorl ventricose. 

 Outer lip thin, inner lip somewhat callused. Entire surface smooth, that is 

 covered by closely crowded concentric striae, which show a decided retral 

 curve at the periphery and indicate a notch on the aperture. These striae 

 are crossed by faint revolving striae of unequal size. Diameter of the shell 

 across the top 28 mm. 



Habitat. Genesee province ; Chautauqua subprovince. The type 

 specimen, a flattened shell, is from the shales at Fox's point, Lake Erie, 

 and was found attached to a calyx of Melocrinus. Another specimen hav- 

 ing about the characters here described has been obtained from the Melo- 

 crinus bed above the Styliolia limestone in Blacksmith gully, Bristol, 

 Ontario co. (Naples subprovince). 



1 Loc - di. pL 5- fi g- 5- 



