NAPLES FAUNA IN WESTERN NEW YORK, PART 2 26 I 



Dimensions. This specimen has a length of 15 mm, and a width of 

 18 mm. 



Habitat. Genesee province ; Naples subprovince. From the sandy 

 layers in the upper part of the group ; Tannery gully, Naples. A shell 

 which may prove to be this species occurs in the Chautauqua subprovince 

 in the higher beds at Varysburg, Wyoming co. 



paraptyx gen. nov. 

 With this name it is proposed to designate shells showing an inter- 

 esting departure from Honeoyea and yet withal closely allied to that genus 

 and connected therewith by the species Honeoyea desmata. The 

 type species of Paraptyx (P. Ontario) is of considerable size, much larger 

 than is attained by Honeoyea, and its surface markings are the fine, 

 radial, simple or compound plications of the " Cardiolas " rather than 



Fig. 11 Paraptyx Ontario, Posterodorsai margin or 

 crescent viewed from within 



the crested ribs of Honeoyea. When oriented to correspond with that 

 genus, we find that the beaks are opisthogyre, and that there is a sharply 

 defined posterior " crescent " with vertical or slightly incurved face and 

 elevated ridge ; the surface of this crescent bears a few strong plications, 

 interlocking at their ends on opposite valves. The crescent is almost trans- 

 verse or on the plane of the hinge and is relatively short. Its outer 

 extremity, unlike that of Honeoyea, is effected. On the interior the cres- 

 cent and ridge make a deep sinus, as if for the passage of some siphon, but 

 for want of an analogy we can not venture an opinion of its function. 

 Conceding this crescent to be posterior and the beaks directed backward, 

 the anterior margins of the shell were very slightly if at all opened. Our 

 material bearing on this point is not very extensive but indicates close 

 apposition along these margins. Beneath and in front of the beak the 

 cardinal line is smooth, without ligament area. 



