338 BULLETIN 152, UNITED STATES NATIONAL MUSEUM 



bunch of shells or piles a lot of small shells together over a depression 

 in the mud in which it lives." 



Range of the species. — From Boston, Massachusetts, to Flori- 

 anopolis (or Desterro), Brazil; Bermuda. Occasional or accidental 

 north of New Jersey. 



The typical form is more northern than any other. There are 

 specimens in the National Museum from Woods Hole (^lassachu- 

 setts), Newport (Rhode Island), Chesapeake Bay (Maryland and 

 Virginia), South Carolina and Florida (as far as Cedar Keys) ; Bermuda 

 (VerrUl). 



Beaufort (North Carolina) is the most northern occurrence of 

 forma obesa; it is known also from South Carolina, Florida Keys, 

 west Florida, Louisiana, Cuba, Jamaica, St. Martin (Dutch West 

 Indies), Curagao, southern Brazil (from Bay of Rio de Janeiro to 

 Florianopolis) ; Bermuda. 



Forma crassa ranges from western Florida through the West Indies 

 to Trinidad, and by way of Honduras, Panama and Colombia to 

 central Brazil (from Mamanguape to the State of Rio de Janeiro); 

 Bermuda. 



Forma simpsoni is the prevailing, though not the exclusive, form 

 in the Gulf of Mexico, as, in west Florida and Texas; it has been 

 taken occasionally in South Carolina, where also various forms inter- 

 mediate between the typica and simpsoni occur. 



Material examined. — 



MASSACHUSETTS.— Boston (M.C.Z.). 



Vineyard Sound; 1875; 1 specimen (P.M.Y.U.). 



Woods Hole; January 8, 1876; Vinal N. Edwards, U. S. Fish Com- 

 mission; 1 specimen (4:0012), forma typica. 



Buzzards Bay shore of Pasque Island, Elizabeth Islands; 6}i- 

 7)2 fathoms; Sh. M.; July 12, 1905; station 84, Phalarope, Bureau of 

 Fisheries; 1 young (Woods Hole Station). 



RHODE ISLAND.— Newport; shore; 1880; U. S. Fish Commis- 

 sion; 2 males, 1 female (4539, 401 14), /orma typica; 2 males, 1 young 

 female (P.M.Y.U.). 



Drownville (M.C.Z.). 



NEW JERSEY.— Maurice River Cove; November 16, 1928; 

 H. G. Richards; 1 male, forma typica; returned to University of 

 Pennsylvania. 



MARYLAND.— Mago thy Bay; on coon oysters; July 22, 1916; 

 Fish Hawk; 2 males, 1 ovigerous female (56266), /onna typica. 



VIRGINIA.— Smith Island; December 24, 1898; Wilham Palmer; 

 1 female (22328), forma typica. 



Eastern shore of Chesapeake Bay: 1 female (42811), forma typica, 

 from Union College. H. E. Webster; 1 male (56837), almost typica, 

 varying toward simpsoni, from Boston Society of Natural History. 



