1 82 BULLETIN OF THE BUREAU OF FISHERIES. 



thus eliminated a large number of forms which are relatively uncommon in these waters. 

 The remaining ones, on the other hand, being, for the most part, of comparatively 

 common occurrence, are just those whose general range of distribution is probably 

 known with the greatest accuracy. Such a list, of course, comprises only bottom- 

 dwelling organisms which occur at depths sufficiently great to be taken by the dredge. 

 It consequently excludes the littoral and pelagic life as a whole, and therefore does not 

 represent every element of the fauna. 



Before entering upon such an analysis, however, it may be of interest to consider 

 some of the prevalent opinions regarding the distribution of marine animals and plants 

 upon this section of the coast. 



It has been pretty generally assumed that Cape Cod forms a rather definite bound- 

 ary between the fauna and flora inhabiting the regions above and below it. This was 

 urged by Gould as early as 1840 (see Gould, 1840, p. 491), as the result of a study of 

 the distribution of marine mollusks. Gould asserts that "many whole genera do not 

 pass from one side to the other of this limit. Of the 203 marine species, 81 do not pass 

 to the south and 30 have not been found to the north of the Cape, though many of 

 them approach within a very few miles of each other." It was the opinion of Dana, 

 likewise (1852, 1853), that there occurred at Cape Cod "a remarkable transition in 

 species, and a natural boundary between the south and the north." Dana recognized 

 four zoogeographical divisions of the Atlantic coast of North America, viz, the Acadian 

 (first called by him "Nova Scotian"), Virginian, Carolinian, and Floridan. Cape Cod, 

 he believed, served to divide the Acadian, lying to its north, from the Virginian on the 

 south. Packard sought to distinguish another region, the "Syrtesian," on the north of 

 the Acadian, between the latter and the arctic or polar." 



From a consideration of the actinians and echinoderms, in particular, Verrill (1866) 

 was led to the belief "that there are portions of three distinct Faunae to be distinguished 

 on the coast of New England, viz: First, that known as the Virginian Fauna, extending 

 from Cape Hatteras to the southern side of Cape Cod. * * * Second, that known 

 as the Acadian or Nova Scotian Fauna, which extends along the shore from Cape Cod to 

 the mouth of the St. Lawrence River, and includes * * * and many of the banks 

 to the southward of Cape Cod, such as Nantucket Shoals; and perhaps the extreme end 

 of Long Island. * * * Off the coast of New Jersey, also, there are deep-lying banks 

 or shoals, which may be referred to this Fauna. * * * Third, a more arctic Fauna 

 characterizes the eastern coast of Labrador and Newfoundland, and the Grand Banks, 

 which extends far southward along our coast in deep water, influenced by the polar 

 current of cold water '' which skirts the northern part of our coast." This is the "Syr- 

 tesian" fauna of Packard. 



Later (1871), referring especially to his dredging operations in Vineyard Sound and 

 vicinity, Verrill writes: "One of the most important of the results of these investiga- 

 tions * * * is that while the shores and shallow waters of the bays and sounds, as 

 far as Cape Cod, are occupied chiefly by southern forms, or the Virginian fauna,*^ the 

 deeper channels and the central parts of Long Island Sound, as far as Stonington, Conn., 

 are inhabited almost exclusively by northern fonns, or an extension of the Acadian 

 Fauna." 



o GUI, 1873, p. 782, likewise recognizes the Arctic, Syrtesian, Acadian, Virginian, and Carolinian faunas. 

 ^ Concerning the probability of the existence of such a current, see Chapter II of the present report. 



<■ Perkins, on the other hand, from a consideration of the tnoUusks of the vicinity of New Haven, wrote in 1869; "The fauna 

 of the region belongs about equally to the Acadian and Virginian faunae. 



