41 



the cavities of old shells. Dimensions of the largest 

 specimen in my collection : L. j^-^ ; B. y6_ ; Th. ^•5^- 



2. tenera, Turton ? (See Forbes^ in Mag. Nat. 

 Hist. V. 8, p. 594, fig. 64.) 



Shell much stronger than the last, dilated towards 

 the frontal margin, compressed, gaping on all sides, 

 ribbed longitudinally. Animal having the mantle 

 yellowish-white, bordered with bright red ; filaments 

 pale yellow tipped with red, and short as compared 

 with those of the other two species. 



In deep water on the north coast ; not frequent. 



Dimensions : L. 1. f^ ; B. -f^ ; Th. f^. 



3. inflata. Lam. ? (See Mag. of Nat. Hist. v. 8, 

 p. 593, fig. 63.) 



Shell strong, inflated, with rough longitudinal ribs, 

 crossed by lines and furrows of growth ; gaping on 

 all sides w^idely. Animal with very long bright red 

 filaments. 



In deep water on the north coast ; rare. 



Dimensions^: L. \^ ; B. f^ ; T. ^^. 



A Norwegian naturalist, M. Sars of Bergen, has 

 figured this species with its animal, and refers it with 

 a query to the Lima linguatula of Lamarck. 



Fam. Arcacea. 



LX. Area, Lin. 



1. tetragona, Poll. 

 Shell oblong, quadrangular, very tumid, gaping in 

 front, brownish- white, with regular longitudinal and 

 irregular transverse stride ; an oblique rib from the 



