506 REPORT OF COMMISSIONER OF FISH AND FISHERIES. 



RADIATA. 



JEchinoderms. 



Page. 



tStereoderina unisemita 503 



t*Echinarachnius parina 503 



Strongylocentrotus Drobach- 



iensis 406 



Page. 



Asterias vulgaris 496 



*Oribrella sanguinolenta. . . 407 

 Opbiopbolis aculeata 496 



Acaleplis. 



Page. 



*Plalypyxis cylindrica 408 



*Clytia Johnstoni 408 



Eudendriurn ramosum 408 



Pas;e. 



*Plumularia, sp 407 



Hydi'actinia polyelina ..... 328 



Polyps. 



Page. 

 Edwardsia lineata 497 



Page. 

 Alcyonium carneum ....... 497 



PROTOZOA. 



Sponges. 



Page. 



Cbalina oculata 497 



Polymastia (?) 497 



Page. 



fMassive siliceous sponge . . 503 

 IV. 5. — Fauna of the muddy bottoms off the open coast. 



Within tbe depths to which our dredgings extended r very few true 

 muddy bottoms occur. The deposits of mud on the open coast usually 

 begin to occur only at the depths of twenty -five to thirty fathoms, and 

 even at these depths there is a considerable admixture with fine siliceous 

 sand. The central and deeper portion of the depression in line with the 

 axis of Vineyard Sound is, however, occupied off to the west of Gay 

 Head and No Man's Land by a deposit of fine, soft, sticky mud, filled 

 with the tubes of Annelids and Amphipods, (Ampelisca, &c.) Dredgings 

 were made on this bottom at localities 85, c, in 18 fathoms ; d, 19 fathoms ; 

 e y 11 fathoms. On September 9, the temperature at 85, c, was 58° Fah- 

 renheit at the bottom, and 62° at the surface; at d, it was 57° at the 

 bottom and 62° at the surface ; at e, it was 59° at the bottom and 63° at 

 the surface. Tbis muddy bottom abounded in Annelids, small Crustacea, 

 and bivalve shells. 



In several other localities, where the bottom was a mixture of mud 

 and fine sand, the mud seemed to predominate and to determine the 

 character of the life, so that such localities have been classed with the 

 muddy bottoms, though the fauna differed considerably from that of the 

 soft muddy bottoms referred to above. In the following list, however, I 

 have specially designated tbe species found in the typical localities of 

 each kind. 



