Io6 BULLETIN OF THE BUREAU OP FISHERIES. 



At least two of the foregoing species (Membranipora tenuis and Hippothoa hyalina) , 

 while occurring with some frequency in the Bay, are restricted for the most part to the 

 neighborhood of land. 



The preponderance of some of these forms in the Vineyard Sound records is prob- 

 ably due in part to the relative imperfection of our data for Bryozoa from Buzzards 

 Bay. Supplementary dredgings in the Bay, during the summer of 1909, revealed the 

 presence of a number of species not hitherto found there, and indicated that certain 

 others were not so scarce in this body of water as had been supposed. Indeed, it has 

 been necessary to remove certain species from this second list which had earlier been 

 placed there. Concerning the following species it is not believed that we have sufficient 

 data to warrant any conclusions as to their relative abundance in the Bay and the Sound : 



Tubulipora liliacea. 

 Membranipora monostachys. 

 Bowerbankia gracilis. 



As a matter of fact all three of these species are recorded from an absolutely greater 

 number of stations in the Sound than in the Bay. One of them {Membranipora mono- 

 stachys) has been recorded in the latter only from the stations near land. 



Aside from the few cases mentioned, in which the occurrence of certain species in 

 the Bay is limited to the inshore waters, there is nothing in the distribution of any of 

 the species, so far as shown by the charts, which can be regarded as in any sense "bathy- 

 metric." Certain species which do not appear in our distribution charts, however, are 

 restricted to shallow waters, or to the immediate neighborhood of land, and indeed may 

 find their proper habitat in the littoral or intertidal zone. The most familiar instance of 

 the last sort is the abundant Flustrella hispida, which occurs in great profusion upon the 

 rockweeds, Fucus and Ascophyllum. Certain other species, likewise, such as Eucratea 

 chelata, Amaihia dichotoma, and Bugula fiahellata, have seldom been encountered by us 

 except upon piles. Another species, Membranipora tehuelcha, has only been noted upon 

 the floating gulf weed, with which it is borne passively to our waters. This, like so many 

 other species having the same habitat, is a southern form which does not properly 

 belong to our local fauna. 



Not a single instance has been found among our dredging records of a species of 

 this group whose distribution in Vineyard Sound and Buzzards Bay appears to be 

 determined by temperature. There dwell, however, within the outlying colder waters 

 of the region considered by us, a considerable number of species, most of which repre- 

 sent a strictly northern fauna, and many of which, indeed, find in Woods Hole or vicinity 

 their southern limit of distribution. A number of these have not previously been re- 

 corded south of Canada. A list of those species is presented, herewith, which have been 

 taken by us at Crab Ledge or in the vicinity of Nantucket, but not within Vineyard 

 Sound or Buzzards Bay. Data are included respecting their distribution as heretofore 

 known. 



Crisia cribraria Canada. 



Stomatopora diastoporoides . . . .British Isles, Baffins Bay, Gulf of St. Lawrence. 



Tubulipora atlantica North Atlantic from Labiador to Florida: Australia. 



Tubulipora flabellaris Northern Atlantic and Arctic seas; Greenland, Gulf of St. Lawrence, 



Grand Manan; Mediterranean? 

 Gemellaria loricata Northern Atlantic and Arctic seas; Labrador, St. Georges Banks, Grand 



Manan. 



