MONOGRAPH OF THE GENUS 



CLEMENTI A. 



Fam. Veneridse. 



Char. Gen. Clementia, Gray. Testa sequivalvis, inaequilatera, 

 tenuis. Cardo dentibus in valva sinistra uno erecto antico, duo- 

 bus obliquis laminatis posticis ; in valva, dextra duobus erectis 

 anticis, uno bifido laminato postico ; in utraque valva. area trigona 

 ante dentes posita. Impressiones musculares duse; impressio 

 pallii sinu magno. 



The very thin, light character of the Venus papyracea, and the 

 peculiar form of its hinge, constitute the reasons given for its 

 separation from the genus Venus. The hinge is thin, having one 

 anterior erect tooth, and two posterior laminated teeth in the 

 left valve locking into two anterior erect teeth, and one posterior 

 laminated tooth in the right, with a triangular area in front of 

 the teeth in each valve. The sinus in the impression of the 

 mantle is deep. 



1. Clementia papyracea (pi. cli. f. 155), Gray, Wood, 

 Suppl. pi. 2. f. 8. 



C. testa oblique ovali, inflata, alba, postice oblique subacumi- 

 nata, antice brevi, subrotundata ; margine dorsali declivi, subex- 

 cavato; lunula indistincta, impressa; margine ventrali arcuato; 

 undis concentricis latis ad umbones elevatis, prope marginem 

 ventralem evanidis. 



Obliquely oval, swelled, white, rather tapering and acuminated 

 at the back, rather short and rounded in front, concentrically un- 

 dulated with broad ridges, which are large and conspicuous near 

 the umboes, but almost disappear near the ventral margin. 



New Holland. 



2. Clementia similis (pi. cli. f. 156), Sowerby,jun. 



C. testa, parva, C. papyracece simili, sed rectiuscula, antice pau- 

 lulum subtruncata, postice baud tanturn attenuata. 



