310 MARINE INVERTEBRATES 



barrier and maintain themselves very successfully at Martha's 

 Vineyard and in Long Island Sound. Some of the species whose 

 natural habitat is south of Cape Cod are also to be found north 

 of that point, but they do not reach their full development in the 

 colder waters of Massachusetts Bay. 



The long stretch of coast-line from Cape Cod to Florida is 

 easily susceptible of faunal subdivision at Hatteras, below which 

 locality a decided mixture of Antillean species is apparent. Be- 

 tween Long Island Sound and Hatteras the littoral molluscaii 

 fauna is disappointing to the collector, for the number of species 

 is relatively small, and few even of these are entitled to r .ay claims 

 to beauty of shell. The nature of this coast, virtually a great 

 sweep of exposed sand-beach, is not conducive to a varied or rich 

 fauna. But if this portion of the transatlantic province is lack- 

 ing in interest to the shell-collector, it is anything but disappoint- 

 ing to the army of men employed in the oyster- and clam-fishery. 

 It is only within this faunal area that the American oyster, Ostrea 

 virginica, the best of the edible shell-fish, finds its natural home, 

 and here the oyster-culture is most extensively carried on. 



After storms the Jersey beaches are frequently strewn with 

 Mactra, Tagelus, Area, and Ensis ; in more sheltered places Fulgur 

 and Polynices (Lunatia) are commonly met. These may be ac- 

 cepted as the most characteristic genera of this province. 



Just south of Cape Hatteras an observer is struck with the 

 sudden change in the appearance of the shells on the beach. 

 Cardinal, Cassis, Dolinm, Area, and Cancellaria at once suggest 

 the West Indies. About the vicinity of Hatteras the Gulf Stream 

 approaches very near the land, bringing with its warm waters 

 many wanderers from tropical homes. From Beaufort to Florida 

 there is another long stretch of exposed and shifting sand-beach, 

 which offers a scant return to the collector of mollusks. 



THE CARIBBEAN PROVINCE 



When Florida is reached a new world is opened to the natural- 

 ist, for there a better acquaintance is made with the great Carib- 

 bean province, which, extending from Florida to the northern 

 shores of South America, embraces all the Bahamas, the West 



