500 REPORT OF COMMISSIONER OF FISH AND FISHERIES. 



RADTATA. 



Ecliinodcrms. 



Page. 



tStereoderina unisemita 503 



t*Ecliinaracbnius pariua 503 



Stronoyloceutrotus Drobacli- 

 iensis J^OO 



Asterias vulgaris 



*Cribrella saiiguiuolenta. 

 Ophiopbolis aciileata . . . . 



Page. 

 496 

 407 

 490 



Acale/plis. 



Page. 



*Platypyxis cyliudrica 408 



*Cly tia Johustoui 408 



Eudendriiim ramosuni 408 



Pa.ge. 



*PIu miliaria, sp 407 



Hydractinia polycliua. .... 328 



Polyps 



Page. 

 Edwardsia liueata 497 



Page. 



Alcyouium carnoum 497 



PROTOZOA. 



Sponges 



Page. 



Cbalina oculata 497 



Polymastia (?) 497 



Page. 



503 



tMassive siliceous sponge . . 

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



Within the depths to which our dredgiugs 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, {Ampelisea, &c.) Dredgiugs 

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

 c, 11 fathoms. On September 9, the temperature at -85, c, was 53=^ Fah- 

 renheit at the bottom, and C2^ at the surface; at d, it was 57° at the 

 bottom and 02° at the surface ; at e, it was 59° at the bottom and 63° at 

 the surface. This 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 the species found in the typical localities of 

 each kind. 



