SCAPHANDER. 445 



George Humphreys mentions Cylichna cylindracea also. 

 The Dentalium and Ditrupa, when sticking in the giz- 

 zard, look like spits through joints of meat. Accor- 

 ding to Landsborough (' Zoologist/ 1843, pp. 87, 88) 

 " though they seem to indulge very freely as to quantity, 

 they appear to be wiser than our biped gourmands; for 

 they keep to one dish. In every one of the specimens 

 I procured, the capacious gullet was filled with the fry 

 of Mactra subtruncata. The gullet was in the form of 

 a cornsack, quite distended, for each contained some 

 scores of these little bivalve shells in an unbroken state. 

 The sack, however, gradually emptied itself into the 

 gizzard ; and in this shelly mill the shells and their 

 contents were reduced to powder, or rather a fine paste, 

 well fitted, no doubt, to be wholesome nutriment for 

 the industrious little marine miller/' The plates of the 

 gizzard are white, with the middle portion of the inside 

 brownish-yellow and raised, the centre being white and 

 ground down by use. The side-plates slope from a boss 

 in the centre to a sharp edge ; and the intermediate or 

 small plate resembles an opera hat : in the young it is 

 not unlike Ancylus lacustj'is. Among other wonderful 

 tales of the sea, the Guernsey fishermen will tell you 

 that the Scaphander bites off a portion of the outer lip 

 of its shell, when it finds itself a prisoner in the trawl- 

 net ! It is preyed on by the haddock. A monstrosity 

 in my collection has the crown deeply and widely 

 channelled. 



Risso described it as S. lignarius and S. giganteus ; 

 the fossil shell of the same species is probably his 

 S. targionius. Bulla zonata of Turton and S. Brownii 

 of Leach are the young; I once thought (but 

 wrongly) that the former might be S. librarius of 

 Loven. 



