288 Panama Shells. MACTRID^:, 



Habitat. Bay of Caraccas ; Ginning ! Sowerby. 



Panama ; 0. B. A. ! 

 4 specimens were obtained. 



480. Cumingia trigonularis. 



Synonymy. 



Cumingia trigonularis Sowb. in Proc. Zool. Soc. Loud. p. 35. Mar. 1833; 



Sowb. Gen. pi. . f. 2. 



Reeve Conch. Syst. pi. 49. f. 2. Sept. 1841,. 



Station. Among stones in deep water ; Cuming ! Sowerby 



Habitat. St. Elena : Cuming ! Sowerby. 

 Panama ; C. B. A. ! 



3 specimens were found. 



481. Cumingia . Sp. indet. ,. 



4 specimens were obtained near Panama. 



482. Cumingia . Sp. indet. 5. 



1 specimen was obtained near Panama. 



483. Cumingia , Sp. indet. c. 



1 valve was found near Panama. 



484. Cumingia - -. Sp. indet. d. 



1 specimen was found near Panama. 



The above are probably new species of Cumingia; but as 

 their characters are probably somewhat variable, more speci- 

 mens are requisite for good descriptions. 



485. Ainphidesma bicolor. Nov. sp. 



Shell elliptical, scarcely flexuous, inequilateral, the posterior 

 side being larger ; with the posterior dorsal margin a little con- 



