96 CATALOGUE OF THE M0LLU8CA 



The foot is large, subtriangular, and strongly kneed or angu- 

 lated behind. It is protruded from the longer end of th§ shell, 

 which in this genus is anterior. We have not been able to de- 

 tect any siphons. Professor Loven was the first to notice that 

 this species, which is the Mesodesma exiguum of his " Index," 

 has an ossicle. By carefully opening some of our specimens we 

 have also observed it. It appears to be a calcification of the 

 lower part of the ligament, which is very easily detached, and 

 is generally wanting in dead shells. We have not found the 

 same process in the following species. 



2. M. SUBSTRIATA, Moilt. 



Ligula suhstriata, Mont. Test. Brit. Supp. 25. 



Taken abundantly by Mr. K Howse, on the spines of Spa- 

 tangus purpureus, from 60 fathoms water, 50 miles off the coast 

 of Durham. 



Mr. Howse's observations on the animal of this species agree 

 with ours on M. bidentata, as to the shape and position of the 

 foot, and the apparent absence of siphons. All the animals of 

 this family appear to attach themselves by a byssus. 



3. M. FERRUGINOSA, Jfow^. 



Mya ferruginosa, Mont. Test. Brit. Supp. 22, t. 26, £ 2. 

 Under stones among the rocks at Oullercoats, and in sand, rare. 



Family. Anatinid^, Gray. 

 109. NE^RA, Gray. 

 1. N. CUSPID AT A, Olivi. 



Thracia hrevirostra, Brown Illust. Rec. Conch. 110, t. 44, 



£ 11—14. 



First noticed on this coast by the Rev. W. Mark, who got two 



individuals from the stomachs of haddocks. From a fishing 



boat, Oullercoats (one specimen). — A. H. Mr. R. Howse has got 



one or two specimens from haddocks at Whitburn. 



110. CORBULA, Bruguiere. 

 1. C. GIBBA, Olivi. 



Mya incequivalvis, Mont. Test. Brit. 38. 



Corbula nucleus, Lam. Anim. s. Vert, 2nd Ed., vi. 139. 



