122 BULLETIN OF THE BUREAU OF FISHERIES. 
With a very few exceptions the last two lists comprise species which primarily 
inhabit muddy shores and bottoms. In the case of certain species (Clymenella and 
Rhynchobolus) it is to be noted that the few records of their occurrence in Vineyard 
Sound refer to areas whose bottoms are known to be partially muddy. This type of 
distribution is not, however, wholly intelligible in the case of Clymenella torquata, since 
it is known to occur in abundance in shores of pure sand. Unlike most of the foregoing 
species, Pista palmata and P. intermedia appear to be restricted, both in the Bay and 
in the Sound, to the adlittoral zone. They are found upon various types of bottom, 
including muddy ones. Platynereis megalops might perhaps have been included. in 
the last of the foregoing lists, since it was recorded more frequently (absolutely as well 
as relatively) from Buzzards Bay. Like the two species of Pista, it was taken much 
more often at the inshore stations. 
As the last of our groups with respect to distribution, we have: 
Species exhibiting no evident preference for one or the other body of water. 
Number of stations. 
INepieliys (DiGerar. . ete etre tenn arieh hae /f iia, she ashe, oneleeibieeute 6 Sound+ 5 Bay. 
Bel bah 2) shes Wl FB Aan na ne a cae 7 Sound+ 5 Bay. 
RIGS PUACE AN CUMALE A ha o's. - oystrntte avateea ae ka ltie eset slid 4 Meese he nel 105 Sound+86 Bay. 
Arabellaropaliaan. aves seme ee te ele ele ad ok Oe haere 27 Sound+17 Bay. 
Parasabelia’ micropathaliitasyi0s. cocle ecoc |. oes odes 6 Sound+ 6 Bay. 
Heydroidessdianthis: . eine tere te once cies vcs sicrdvbateacle 130 Sound-+93 Bay. 
The distribution of most of these last species seems to be entirely independent of the 
character of the bottom. Two of them (Diopatra and Hydroides) are among the most 
ubiquitous of our local Annulata, though it is possible that the distribution of Dzopatra 
is not so general as the wide-spread occurrence of its tubes would lead one to suppose. 
Regarding three of the foregoing species the records are too meager to permit of our 
forming any conclusions of value. Nephthys bucera is probably not of general occur- 
rence in the Bay, since it is known to be predominantly a sand-dwelling species. 
The temperature factor, which has been shown to be such an important one in 
determining the distribution of many species belonging to other groups of organisms, 
probably applies to certain of the local annelids, though it appears to play a relatively 
insignificant part with respect to the species for which charts have been plotted. The 
only case among the latter which seems to fall under this head is that of the serpulid 
worm Hydroides dianthus. The absence of this species from the western portion of 
Vineyard Sound is a conspicuous feature in its distribution, especially when coupled 
with the fact that it has not once been recorded from Crab Ledge, despite the favorable 
bottom at the latter point. It is of probable significance in this connection that 
Hydroides is predominantly a southward-ranging species, which may, on this account, 
be poorly adapted to the colder waters of the region. The case resembles that of the 
coral Astrangia (p. 99) and that of the sea urchin Arbacia (p. 113), which have already 
been discussed from this point of view. So far as our records go, however, there are in 
Vineyard Sound none of those characteristic cold-water species which are confined 
to the neighborhood of the open ocean. But there are a number of species of annelids 
recorded from the Crab Ledge stations alone among the dredgings of the survey. For 
most of such species Cape Cod is believed to lie at the southern limit of distribution. 
Some of these are included in the following table. The statements as to range have 
been furnished us by Dr. Moore. 
