212 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [506] 
RADIATA. 
Echinoderms. 
Page. | Page. 
TStereoderma unisemita..... 505 | Asterias vulgaris........... 496 
t*Echinarachnius parma.... 503 | *Cribrella sanguinolenta... 407 
Strongylocentrotus Drébach- ° Ophiopholis aculeata...... 496 
“DOS 53S eran 406 
Acalephs. 
Page. Page. 
*Platypyxis cylindrica.....- 408 |.*Plumularia, sp-.--2.0 see 407 
*Chytia Johnstont....-....- 408 | Hydractinia polyclina..... 028 
Eudendrium ramosum...... 408 
Polyps. 
Page. Page. 
Edwardsia lineata........-.. 497 | Aleyonium carneum....... 497 
PROTOZOA. 
Sponges. 
Page. | Page. 
Chalina oculata............ 497 | +Massive siliceous sponge... 503 
iRelymastia (2). <0. a2 eke 497 | 
IV. 5.—FAUNA OF THE MUDDY BOTTOMS OFF THE OPEN COAST. 
Within the depths to which our dredgings extended, 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; 
é, 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. This muddy bottom aboundedin 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 the species found in the typical localities of 
each kind. 
