BIOLOGICAL SURVEY OF WOODS HOLE AND VICINITY. 1 55 



Some of these species (Thais lapUlus, Liitorina riidis, Lacuna vincta, Acmcea kstu- 

 dirinhs) are more or less common along shore, but rarely find their way into the dredge. 

 A considerable number of the species were, on the other hand, only taken at Crab Ledge, 

 and thus do not form any part of the fauna of Vineyard Sound or Buzzards Bay. 



The group of oelagic gastropods known as the Pteropoda is represented locally by 

 a few species which are occasionally found in the outlying waters of the region. Only 

 one of these, Cavolum tridentaia, has been met within the dredge, a single shell having 

 been taken near the western end of Vineyard Sound. Such a state of affairs is in striking 

 contrast to the condition in some parts of the Atlantic Ocean, where the remains of 

 this class of mollusks accumulate to such a degree as to form a veritable "pteropod 

 ooze," covering wide tracts of the sea floor. 



IV. CEPHALOPODA. 



Two species of squid, Loligo pealii and Ommastrephes illecebrosus, are found in these 

 waters. Only the former of these has been met with in dredging. Loligo has been 

 frequently taken in the Fish Hawk dredgings throughout both the Sound and the Bay, 

 being recorded from 73 stations (chart 189). It has never, however, been dredged by 

 the Phalarope. This is doubtless due to the active movements of this animal, which 

 would not be readily caught in a small dredge net, although it would be taken with- 

 out difficulty by the beam trawl. The eggs of the squid, on the other hand, were 

 brought up very frequently both by the Fish Hawk and the Phalarope. The range 

 of this species, as stated by Dall, is from Penobscot Bay, Me., to South Carolina. It 

 thus ranks among the predominantly southern species. 



Shells of the little known Spirula peronii sometimes drift to the outer island shores, 

 and one specimen of an octopus (Parasira catemUata) was taken many years ago in Vine- 

 yard Sound. 



10. ADELOCHORDA. 



One species of Balanoqlossus (B. aurantiacus (Girard)) is common at various points 

 along shore, where it burrows rather deeply into the sand or gravel. So far as we know, 

 it has never been taken locally with the dredge. 



II. TUNICATA. 



Tunicates, particularly the compound forms, constitute a conspicuous feature of the 

 fauna of some portions of our local sea bottom. Certain species likewise abound on 

 piles and on eel grass and rockweed along shore, while one or more pelagic forms are 

 occasionally abundant within the limits of our region. The total number recorded, 

 however, is small, only 22 " determined species being included with certainty in our cata- 

 logue; together with about 10 which are unidentified or doubtful. Of these 14(4-6?) 

 were encountered during our dredging operations. The average number of species taken 

 per dredge haul was only i.i, though considerable clusters of Styela partita, associated 

 with Molgula manhattensis, Prrophora viridis, Didemnum lularium, and perhaps other 

 compound forms were at times brought up together. The form having the most general 



o Throughout our records .4 marouciiim peUucidumand "Amaroucium constellaium" were listed separately and treated as 

 independent species. Owing to the ready distinguishability of these two forms and their somewhat ditTerent habitats we have 

 not thought it worth while to readjust our records and computations, despite Dr. Van Name's seeming demonstration of the 

 specific identity of the two 



