138 PROCEEDINGS: BOSTON SOCIETY NATURAL HISTORY. 
Eittorina littorea Linn., abundant; Assiminea modesta Lea, locally 
common; two species of Turbonilla, rare ; Hermaeci cruciata A. 
Ag., rare ; Cratena gymnota ? Couth., rare ; C. pilata Gould, com¬ 
mon ; Tergipes despectus Johnst., rather rare ; Embletonia fuscata 
Gould, rare ; Eolycerella darenptortii nobis, locally not rare; Co- 
rambella depressa nobis, locally not uncommon; Eriphyla lunulata 
Con., rare ; ? ? Lucina filosa Stimps., a drift shell; Macoma sabulosa 
Spengler, a drift shell; Gemma manhattensis Prime, rather rare. 
Doubtless a certain allowance must be made for doubtful identi¬ 
fications and not much importance can be attached to finds of one 
or two dead specimens on the beach, but it appears that there were 
resident at New Haven at least one Astyris, three Odostomias, one 
Rissoa, Skenea, Lacuna, Eittorina irrorata , Pholas, Saxicava, 
Corbula, and Siliqna, which either do not live at Coldspring Harbor 
or are so excessively rare or so excessively local or capricious as to 
have escaped search. Any of them may yet be found there, how¬ 
ever, and some, such as Eittorina irrorata , probably will be. One 
very abundant Chiton, a highly local Assiminea, two species of 
Turbonilla, Eriphyla, and a southern variety of Gemma appear to 
be legitimate inhabitants of Coldspring Harbor, but not of New 
Haven. A comparison of the relative abundance of various spe¬ 
cies emphasizes the difference. 
In Perkins’s list, omitting the non-acclimatized forms imported 
on southern oysters (to which there is nothing corresponding at 
Coldspring Harbor), of the gasteropods 25 — % are “northern,” 
48% are “ southern,” while 27+% are unassignable. Rather curi¬ 
ously the pelecypods give the same figures so that the total is the 
same. In the Coldspring Harbor list, omitting the nudibranchs 
(which apparently were not collected by Dr. Perkins), of the gas¬ 
teropods 14+% are “northern,” 49—% are “southern” while 
36+% are unassignable; of the pelecypods 23+% are “north¬ 
ern,” 52+% are “southern,” while 24+% are unassignable; or for 
the total 18 + % are “ northern ” 50+ % are “ southern ” and 31 + % 
are unassignable. The omission of the nudibranchs emphasizes 
the southern aspect of the fauna on the face of the record, but 
there may well be doubt whether the attribution of many of the 
species to northern waters only is not a mere effect of our lack of 
knowledge of this group. 
Doubtless figures like these give a false impression of accuracy, 
since opinion may differ as to whether to class a species as “ south- 
