AVICULA. Panama Shells. 249 



Station. — Sandy mud, 12 to 20 fathoms ; Cuming I Sowerby. 



Habitat. — Panama and Bay of Caraccas ; Cuming ! Sowerby : 

 also Orbigny. 

 Panama ; C. B. A. ! 

 , We found 1 entire shell and 8 odd valves. 



390. liiina Pacifica. 



Synonymy. 



Lima arcuata Sowb. (non Geinitz 1840) Thes. Conch, p. 86. 



No. 15. pi. 22. f. 41-2. - - - - 1843. 



Hanley Descr. Catal. p. 268. 1845 ? 



Pacifica Orb. Voy. Amer. Merid. Moll. p. 654. 1846. 



Station. — Under stones at the low water mark of the spring 

 tides. 

 Habitat. — Guayaquil and Panama ; Cuming I Orbigny. 

 Panama; Hanley. 

 Panama ; C B. A. I 

 " At Lord Hood's I., under coral rocks ; at Panama, in sandy 

 mud ; at Guayaquil Bay ; at Guacomayo, under stones, &c., by 

 Mr. Cuming." Sowerby. 

 3 specimens were found alive on the reef. 



Family— AYICULID^. 



391. ATicula marg^aritifera ? 



Under the name of A. margaritifer'a are included several 

 kindred but distinct types. It would be of great service to the 

 general subject of the geographical distribution of marine 

 species, if some one would collect authentic materials, and 

 investigate the peculiarities of the local types. 



Station. — ^In the crevices of rocks near low water mark. 



HahitaL—Tahoga ; 0. B. A. I 



"We found only 2 living, rather young, specimens. Probably 



JULY, 1852. 63 Asm. Lto. Nat. Hist. 



