THE NAUTILUS. 57 



edge; hinge teeth small, one in the right valve and two in the left; 

 lateral teeth rudimentary, almost obsolete ; concentric lines of 

 growth very strongly marked. Length 1 inch, height ^"^, breadth 5. 



Linnaeus in 1767, described an European shell under the name 

 of divaricata. Lamarck in 1818 and his followers, supposing our 

 shell to be identical with that of Linnaeus, called it by the same 

 name. The above list of synonyms does not include all the names 

 given by authors to this shell, for several others, besides those quoted, 

 on discovering that our shell was a distinct species, hasten to give it 

 a new name Avithout troubling themselves to ascertain whether or 

 not any one else had i^reviously made the same discovery. Our 

 species has the greatest geographical distribution of any known shell, 

 but does not inhabit Europe. It inhabits from Cape Cod to Brazil, 

 nearly all the Pacific coast of Xorth and South America, the eastern 

 coast of Asia, Seychelles, Isl. Bourbon and Australia, and not only 

 found living, but also as fossils in nearly all these Avidely separated 

 localities. It lives in dee}) water and I have never seen a living spec- 

 imen in Rhode Island, although single valves are plenty on Block 

 Island, Newport and Narragansett Pier. 



Another species, Lucina filosa, inhabiting from Massachusetts 

 Bay to Nova Scotia, has been found some distance off Block Island 

 in 29 fathoms in sandy mud, but I think is hardly entitled to a place 

 among the " Shell-bearing Mollusca of Rhode Island," 



Cryptodon Gouldii, another species of the Lucinidte family, in- 

 habiting deep water and also taken from the stomachs of Codfish, 

 was found at the same time and place with Lucina filosa; also a 

 new species, Cryptodon obesus, A. E. Verrill, described by him in 

 American Journal of Science, 111, 221, 1872. 



FAMILY UNGULINID^. 



Not represented on our shores. 



FAMILY ERYCINID^. 



This family contains twelve genera, three of which are represented 

 in New England, Montacuta, Lepton and Kellia. Species of Mont- 

 acuta and Lepton inhabit the shores north of Cape Cod and have 

 been found in NeAV Bedford Harbor, but no species representing 

 this family have been found in Rhode Island excepting this : 



