136 PROCEEDINGS : BOSTON SOCIETY NATURAL HISTORY. 
Among these, apart from the nudibranchs, are no novelties or 
even great rarities, but the following are not in Professor Verrill’s 
(73) Report on the invertebrates of Vineyard Sound : Littorina 
littorea, Assiminea modesta , Embletonia fuscata , four species of 
Turbonilla, Polycerella davenportii , and Corambella depressa , while 
the range of Astarte undata , Tergipes despectus , Hermaea cruciata , 
and Cratena gymnota is extended west of the localities then known. 
Sanderson Smith and Temple Prime (70) published a report 
on the Mollusca of Long Island which represented eleven years’ col¬ 
lecting and dredging and contained a great number of nominal 
species. It gave to the north side of Long Island inside of Mon- 
tauk Point the equivalents of about 111 modern species, of which 
71, or 64% are in my list which also contains 17 species not in 
Smith and Prime’s list. The additions are Littorina littorea , 
Alexia myosotis, four species of Turbonilla, several nudibranchs, 
and Macoma sabulosa, which last, however, is represented only by 
one worn valve whose occurrence may be accidental. The gaps 
in the list are perhaps more interesting than the occurrences. An 
eastern port where neither Purpura lapillus nor LAttorina Prorata 
occurs is fairly well defined, geographically. Ten years ago it 
might have been possible to define the spot within 60 miles by 
saying it was a place where P. lapillus was not, and X. littorea 
was, found, but now the wave of the conquering European species 
has spread far down toward Virginia and at Coldspring the native 
competitor, JSfassa obsoleta, begins to yield room. The Caecidae, 
Bela, Lacuna, Skenea, Pissoa aculeus , Odostomia impressa and 
0. seminuda , Turbonilla interrupta and T. elegans , the Elysiidae, 
Corbula, Saxicava, Siliqua, Donax, Tellina tenella , Pholas, all are 
conspicuous for absence and another summer might possibly account 
for some of them. 
In the list of the Gasteropods as it stands 18 % are “northern ” 
(i. e. forms characteristic of waters north of Cape Cod and usually 
not extending farther south than New Jersey unless in deep water), 
41% are “southern” (i. e. forms extending south to Hatteras or 
Florida and found north of Cape Cod only in Massachusetts Bay or 
those scattered colonies of southern forms which still dot the coast 
up to Anticosti), while 42% are so general, so local, or so little 
known in distribution as to be unassignable to either category. Of 
the pelecypods 21% are “northern,” 52% are “southern,” and 
27% are unassignable. Or, for the whole, 19+% are “northern,” 
