CERAPUS. 191 



it seems to invest it closely, the Cerapus, whenever anything 

 is in the way which prevents it proceeding, can turn its 

 body without difficulty, and the head may very soon be seen 

 protruding from the opposite end of the tube, so that either 

 extremity may be used as the front part. Say believes that 

 the chief food of the Cerapus consists of the animal of a Ser- 

 iularia, but there is little doubt that, like the Corophium, it 

 feeds on various small marine worms, as well as on other 

 small sea animals. 



Kroyer has met with the Podocerus Leachii in the Baltic ; 

 it lives in a membranaceous tube.* 



Cerapus Whitei, Gosse. — This seems to be very par- 

 tial to the submerged tufts of the Chondrus crispus, that 

 alga which when dry is sold as " Carrageen Moss." Mr. 

 Gosse, who described it in his ' Naturalist's Rambles on 

 the Devonshire Coast/ p. 382, remarks as follows: — "It 

 must be sought at extreme low-water, about the sides of 

 rocks that are laid bare only at the spring-tides of March 

 and September, and the alga itself will be masked under a 

 crowd of Laomedece, Sertularics, Anguinarice, PedicelHn<z 3 

 and other parasitic zoophytes, and half covered with a thick 

 coat of dirty iloccose matter, the ejecta, as I suppose, of these 

 * Nat. Tidssk. iv. 164. 



