DONAX. Panama Shells. 277 



whicli is smaller and higher, at a depth of 6 fathoms in thin 

 mud ; Cuming I Sowerby. 



The only living specimen which we found was buried one or 

 two inches deep in sand, on a sandy flat, near low water mark. 



Habitat, — Gulf of Nicoya ; Cuming 1 Sowerby : also Miiller. 



Tumbez (for the var. above mentioned) ; Cuming I 

 Sowerby : also Miiller. 



Peru and Central America ; Hanley. 



Punta St. Elena ; Jay, 



Panama ; 0. B. A. I 

 8 specimens were obtained. 



454. Donax assimilis. 



Synonymy. 

 Dxmax wisimilis Hanley in Proc. Zool. Soc. Lond. p. 17. Mar. 1845. 



Station. — At about three quarters tide level, buried a few 

 inches deep in sand. It is frequently used for food by the 

 inhabitants. The regard which these moUusks have to a deter- 

 minate level, was shown by a method for finding them, which 

 was employed by a negro woman, who was seen several times 

 collecting them. Beginning below the level where they might 

 be found, the sand was scooped up with a calabash, in a line 

 running up the beach, until the shells were found. Then by 

 keeping to this level, every calabash full of sand yielded more 

 or less of the Donax. 



Habitat. — Panama ; Hanley. 



Mazatlan ; Lt. Green I Mus. Essex Inst. 



Panama ; C. B. A. I 

 350 specimens were collected. 



456. Donax gfracilis. 



Synonymy. 

 Donax graeilis Hanley in Proc. Zool. Soc. Lond. p. 16. Feb. 1846, 



JULY, 1853. 70 Akn. Lto. Nat. Hist. 



