104 ON THE NAIADES 



vnlvuld utraque duplicibns ; lateralibus longis curvisque ; margaritd purpurea, 

 aut salmonis colore tinctd. 



Shell trapezoidal, transverse, inequilateral, inflated ; valves rather thick ; beaks 

 slightly elevated and transversely wrinkled ; cardinal teeth compressed and double in 

 both valves ; lateral teeth long and curved ; nacre purple or salmon. 



Hab. Saatee Canal, South Carolina. Professor Ravenel. 



My Cabinet. 



Cabinet of Professor Ravenel. 



Diam. l-l, Length 1-3, Breadth 2'4 inches. 



Shell trapezoidal, transverse, inequilateral, inflated ; substance of the 

 shell rather thick ; beaks slightly elevated, incurved, transversely wrin- 

 kled ; umbones very much swollen ; ligament rather short and thin ; 

 epidermis dark brown, shining; cardinal teeth very much compressed ; 

 lateral teeth long and slightly curved ; anterior cicatrices distinct ; pos- 

 terior cicatrices confluent ; dorsal cicatrices on the superior part of the 

 cavity of the beaks ; cavity of the shell very deep ; cavity of the beaks 

 full and rounded ; nacre purple or salmon. 



Remarks. — The confertus, in its general characters, resembles the 

 complanatus (Solander). It is, however, much more inflated, and dif- 

 fers in having teeth more compressed. The specimens in my cabinet 

 I owe to the kindness of professor Ravenel. These are all without 

 rays. In young specimens they may exist. 



Symphynota Benedictensis. Plate XVI. fig. 48. 



Testa trapezia simili, itisequilatera, transversa, subcompressd, margine dorsali 

 subrecta ; vulvuUs pertenuibus ; 7iatibus subprominentibus, apicibus granulatis ; 

 cicatricibus vix cernendis ; margaritd cceruleo-albd et iridescente. 



Shell trapezoidal, inequilateral, transverse, rather compressed, nearly straight on the 

 dorsal margin; valves very thin ; beaks somewhat prominent, and granulate at tip ; 

 cicatrices scarcely perceptible ; nacre bluish white and iridescent. 



Hab. Lake Champlain. 



