250 Panama Shells. 



these are identical with, the species which occurs abundantly in 

 some parts of the Bay of Panama, and from which pearls are 

 procured. 



392. A vie ii I a sterna, 



Synonymy. 

 Avicula sterna Gould Proc. Bost. Soc. Nat. Hist. p. 93. Nov. 1851. 



Station. Attached to a small species of Gorgona, at the low 

 water mark of the spring tides. 



Habitat. Panama ; E. Jewett ! Gould MSS, 



Panama ; C. B. A. ! 

 10 specimens were collected on the reef. 



393. Pema . Sp. indet. a. 



Station. Under stones and in the crevices of rocks at low 

 water mark. 



Habitat. La Paz ; Lt. Green ! Gould MSS. 



Panama ; C. B. A. ! 

 130 specimens were collected on the reef. 



394. Perna . Sp. indet. b. 



With the preceding : 30 specimens were collected. 



Family MYTILID^E. 

 395. Pinna maura. 



Synonymy. 



Pinna maura Sowb. in Proc. Zool. Soc. Lond. p. 84. June 1835. 

 HanleyDescr. Catal. p. 255. 1845? 



Station. Muddy banks ; Cuming I Sowerby. 



Habitat. Panama ; Cuming ! Sowerby. 

 Panama ; Hanley I 



