AND OTHER FAMILIES. 41 



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



Shell elliptical, transverse, inequilateral, somewhat inflated ; substance 

 of the shell not thick ; beaks rounded, having short radiating folds ; 

 ligament rather short ; epidermis dark brown and wrinkled ; cardinal 

 teeth long, oblique, nearly parallel with the margin and double in both 

 valves ; lateral teeth long, slightly curved and separated from the car- 

 dinal teeth by the absence of a plate ; anterior and posterior cicatrices 

 both confluent ; dorsal cicatrices situated across the cavity of the beaks : 

 cavity of the beaks rounded and not deep ; nacre very pearly, milk 

 white, iridescent behind. 



Remarks. — I am indebted to the kindness of Dr Ward of Salem, for 

 a perfect specimen of this species. In outline it approaches the 

 U. marginalis (Lam.), but is less transverse. In the characters of 

 its teeth it closely resembles that species. It differs from it in being 

 more inflated, more wrinkled and in having a thicker nacre. In the 

 possession of radiated folds on the beaks it differs altogether. 



On the base of the cardinal tooth, near to the great cicatrix, there is 

 a small deeply impressed cicatrix, resembling in its characters that of 

 the Hyria amcularis (Lam.), mentioned at page 67, Vol. IV. 



The specimen here figured belongs to the fine cabinet of Mr Hyde. 



Symphynota globosa. Plate IV. fig. 12. 



Testa valde globose/, inaequilatcrali, ptllucidd ; valvidis tenuiculis, natibus ro- 

 (undissimis, incurvis ; epidermide luted, Ixvissimd ; dentibus cardinalibus lami- 

 natis, lateralibus elevatis et laminatis ; niargaritd albd et iridescenfe. 



Shell very globose, inequilateral, translucent ; valves rather thin ; beaks very round, 

 incurved; epidermis very smooth and pale yellow; cardinal teeth lamellar; lateral 

 teeth elevated and lamellar ; nacre pearly white and iridescent. 



Hab. River Ohio, 150 miles below Louisville. Col. Long. 



My Cabinet. 



Cabinet of the Academy of Natural Sciences of Philadelphia. 



Cabinet of Peale's Museum. 



VOL. V. — L 



