DESCRIPTION OF FIFTY-TWO SPECIES OF UNIONID^. 43 



Unio cuspidatus. pi. 14, fig. 40. 



Testa Isevi, lata, subinflata, ad latere parum curvata, valde inasquilaterali, postice cuspidata, subblan- 

 gnlari, antice rotundata; valvulis crassiusculis; natibus prominulis, fere terminalibus; epidermide 

 tenebroso-olivacea, eradiata, transverse vittata et polita ; dentibus eardinalibus parvis, subcom- 

 pressis, corrugatis, in utroque valvulo duplicibus ; lateralibus longis, lamellatis subreetisque ; 

 margarita alba et valde iridescente. 



Shell smooth, wide, somewhat inflated, somewhat curved at the side, very ine- 

 quilateral, pointed behind, subbiangular, rounded before ; beaks somewhat promi- 

 nent, nearly terminal ; epidermis dark olive, without rays, transverely banded and 

 polished; cardinal teeth small, somewhat compressed, rough, double in both valves; 

 lateral teeth long, lamellar and nearly straight ; nacre white and very iridescent. 

 Proc. Acad. Nat. Sci., 18t2, p. 159. 

 ijrt&.— Buckhead Creek, Burke Co., Geo., Bishop Elliott; and Abbeville Dist, 



South Carolina, Dr. Barratt. 



My cabinet. 

 Diam. -7, Length 1-3, Breadth 2-7 inches. 



Shell smooth, wide, somewhat inflated, somewhat curved at the side, very ine- 

 quilateral, pointed and subbiangular behind, rounded before; beaks somewhat 

 prominent and nearly terminal ; ligament long, thin and light brown ; epidermis 

 dark olive, without rays, transversely banded, with rather close lines of growth and 

 shining ; umbonial slope rounded ; posterior slope slightly carinate, narrow ellip- 

 tical; cardinal teeth small, somewhat compressed, rough and double in both valves; 

 lateral teeth long, lamellar and nearly straight ; anterior cicatrices distinct, rather 

 large and somewhat impressed; posterior cicatrices confluent, large and slightly 

 impressed ; dorsal cicatrices placed over the centre of the cavity of the beaks ; 

 cavity of the shell shallow and wide; cavity of the beaks very shallow and rounded; 

 nacre white and very iridescent. 



Remarks. — Some years since, among the many new and fine species sent to me 

 by the late Bishop Elliott, were two of the above described species, one of which 

 is only half grown. The description was delayed in hopes of getting more speci- 

 mens, which I had failed to do until two half-grown specimens came from Dr. 

 Barratt. In outline it is near to Barrattii (nobis) and approaches that of Burkensis 

 (nobis). It difi"ers from the former in having a less pronounced umbonial slope, in 

 having a thinner shell, less greenish and in being polished ; also, in being rayless. 

 In the color and polish of the epidermis it is like Burkensis, but it is wider in propor- 

 tion, rather more inflated and more pronounced in the umbonial slope. It has also 

 some resemblance to naviculoides (nobis). The lines of growth are rather close and well 

 defined. The beaks are too much eroded in these specimens to display any character. 



