290 Panama Shells. MACTRIDJE, 



radiating striae over the whole surface: beak small, approxi- 

 mate : left umbo more convex than the right one : corselet and 

 lunule long and narrow, concave. It is closely allied by varieties 

 to A. ellipticum Sowb. : it corresponds mostly to the descriptions 

 of A. lenticulare Sowb., but the figures of that species in Sowb. 

 Conch. HI. and Hanley App. Wood Ind. appear to represent a 

 distinct species. 



Sometimes the shell is tinged with brownish orange near 

 the beaks and middle portion, especially in the interior. In 

 some specimens the inner surface within the pallial line is finely 

 and deeply punctated, and the deep pallial sinus is marked 

 with striae radiating from the opening of the sinus. 



Length 1.8 inch; height 1.58 inch; breadth .82 inch. 



Station. Unknown. 



Habitat. Panama ; 0. B. A. ! 



18 specimens were taken on the reef at low water mark. 



488. AmpMdcsma pulchriim. 



Synonymy. 



Ainphidesma pulchrum Sowb. in Proc. Zool. Soc. Lond. p. 57. Mar. 1832. 



- Mull. Syn. Test. Viv. p. 221. May 1836. 



- Sowb. Conch. 111. No. 2. pi. 17. f. 2. 1841. 



- Reeve Conch. Syst. pi. 47. f. 2. Sept. 1841. 



- Hanley Supp. Wood Ind. Test. pi. 12. f. 6. 1845 ? 



- Hanley Descr. Catal. p. 45. 1845 ? 

 Orb. Voy. Amer. Merid. Moll. p. 534. 1846. 



/Station. Unknown. 



Habitat. Bay of Caraccas ; Cuming ! Sowerby in Proc. Zool. 



Soc. : also Miiller. 

 Bay of Caraccas ; Orbigny. 

 St. Elena and Panama; Cuming! Sowerby in 



Conch. 111. 

 S. America; Hanley. 



