CUSHMAN: VINEYARD SOUND OSTRACODA. 
3(31 
This would seem to indicate that in this protected, somewhat brack¬ 
ish body of water, there may be a definite succession of species during 
the season. More detailed observations are necessary, however, to 
make this more than a suggestion. 
Relations of the Fauna. 
In the region studied there is apparently a very decided difference 
in the fauna of the deeper, colder waters of Vineyard Sound and the 
shallow, warmer portions, such as the harbors, and of the more or 
less enclosed bodies of water, such as the Eel Pond. The condition 
of the bottom also seems to have a considerable influence, for certain 
species are found on sandy bottoms only, others where there is mud 
only. 
Sixteen of the species are identical with those of European waters, 
including the Mediterranean. Of these all but one, Cytheridea rubra, 
are fairly northern species, most of which extend around the whole 
northern Atlantic. As far as can be judged, a number of these which 
occur only in the deeper, colder parts of Vineyard Sound are here 
near their southern limit. They may be compared with Cancer 
borealis, Strongylocentrotus drobachiensis, and other species which 
are decidedly northern in all their characters, yet are found in this 
region in such places. Certain of the species described as new are 
allied to certain of the European species, as mentioned in connection 
with the two species of Sarsiella. Others seem to be entirely different 
and may represent species which are more southern in their range 
and which are probably confined to this side of the Atlantic. 
Many species of Ostraeods have been described from shell charac¬ 
ters alone and in some of these cases it has been possible to supply 
figures of the soft parts. In the new species described as many of the 
parts as possible are figured. 
The synonymy is not essentially complete, since only those refer¬ 
ences are cited which bear on the Atlantic fauna. 
