450 A. K VerriU— Marine Fauna off New England Coast. 



mud-dwelling creatures. Other fishes, those with sharp tails 

 especially, burrow actively into the mud or sand, tail first, and 

 in all probability Macrurus, abundant in this region, has this 

 habit. Several species of eels and eel-like fishes are very 

 abundant on these bottoms. These are all burrowers. The 

 "slime-eel " or hag (Mysuie : r>,i, ■,<,■<!) was also taken in large 

 numbers, both in the trawl and in traps. Many crabs and 

 allied forms are active burrowers. Such creatures, by stirring 

 up the bottom-sediments continually, would give the currents 

 a chance to carry away the finer and lighter materials, leaving 

 the coarser behind. 



In many localities, in the region under consideration, there 

 are great quantities of dead shells, both broken and entire. 

 A small proportion of the bivalves have been drilled by car- 

 nivorous gastropods, but there are large numbers that show no 

 injury whatever. There is no doubt, in my mind, but that 

 these have, for the most part, served as food for the Btar-fisbes, 

 so abundant on these grounds, and from which I have often 

 taken entire shells, of many kinds, including pteropods. Many 

 fishes, like the cod, haddock, hake, etc., have the habit of 

 swallowing shells entire, and after digesting the contents, they 

 disgorge the uninjured shells, and such fishes abound here. 

 The broken shells have probably been preyed upon by the 

 crabs and other Crustacea, having claws strong enough to crack 

 the shells. The large species of Cancer and Oeryon, and the 

 larger Paguroids, abundant in this region, have strength suffi- 

 cient to break most of the bivalve shells. Although I have 

 often seen such Crustacea break open bivalves for food, I am 

 well aware that they also feed on other things.* Many fishes 

 that feed on mollusca break the shells before swallowing them, 

 so that both fishes and crabs have doubtless helped to accumu- 

 late the broken shells that are very often scattered abundantly 

 over the bottom, both in deep and in shallow water. Such 

 accumulations of shells would soon become far more extensive 

 if they were not attacked by boring sponges and annelids. 

 Certain common sponges belonging to the genus Clio n a very 

 rapidly perforate the hardest shells, in every direction, making 

 irregular galleries, and finally utterly destroying them. In our 

 shallower waters the most destructive species is C. sulphurea 

 (Desor), which burrows in shells and limestone when young, 

 but later grows into large, rounded, sulphur yellow masses, 





