on North- Sea Dredging. 



391 



CONCIIIFERA. 



Anomia epliippium, L. 



, var. squamula. 



, var. aculeata. 



Osti'ea edulis, L. 



Pecten pusio, L. 



varius, L. 



opercularis, L. 



, var. lineata, Da Coda. 



tigrinus, Mull. 



, var. costata. 



Lima Loscombii, G. Sou: 



MytiTus edulis, L. 



modiolus, L. This species 



attains a monstrous size in 40 

 to 50 fathoms on hard ground, 

 and makes sad work with the 

 dredges ; one specimen has been 

 found 9 inches long. It grows 

 equally large in the Hardanger 

 Fjord, Norway, in 200-300 

 fathoms. 



Modiolaria marmorata, Forbes. 

 Veiy large. 



nigra, Gray. This also at- 

 tains a very large size, our 

 largest being 2£ inches long. 

 It is found with Mytilus modi- 

 olus. 



Nucula nucleus, L. 



, var. radiata, F. Sf H. 



nitida, G. Sow. Very fine. 



* , var. turgida, Marshall. 



Shell more triangular and beaks 

 more swollen. Corresponding 

 with the deep-water varieties 

 of JV. nucleus and N. tenuis. 



Leda minuta, Mull. Very fine. 



Pectunculus glycimeris, L. 

 *Arca imbricata (?), Poll. [Associ- 

 ated with ordinary Doggerbank 

 shells, such as Fusus norvegi- 

 cus, F. Turtoni, &c. Fishermen 

 often bring us masses of Filo- 

 grana complexa, from one of 

 which I extracted the speci- 

 mens which Dr. Jeffreys has 

 referred to A. imbricata. I do 

 not, howeve: , detect the notched 

 inside margin ; and believe they 

 may with more propriety be 

 referred to A. nodulosa. — Xote 

 by J. L.] 



Montacuta substriata, Mont. 



bidentata, Mont. 



ferruginosa, Mont. We may 



here mention that this species 

 is sometimes quasi-parasitic or 

 11 commensal." In one part of 

 the Channel Islands, between 

 tide-marks, it is parasitic on 

 Spatangus purpureas, in com- 

 pany with M. substriata, but 

 always occupying the opposite 

 end of the Echinid, M. sub- 

 striata occupying the ventral 

 end. It occurs in all stages of 

 growth, from the fry to the 

 adult. 



Kellia suborbicularis, Mont. 



, var. lactea, Brown. 



Lucina boreal is, L. 



Axinus flexuosus, Mont. Small 

 form in mud, 45 fathoms. 



Cardium echinatum, L. 



, var. expansa. 



fasciatum, Mont. 



edule, L. 



norvegicum, Spengl. 



Cyprina islandica, L. 



, var. crassior. 



Astarte sulcata, Da Costa. 



* , var. paucicostata. 



£ , var. minor. 



* , var. incrasaata, Brocc. 



, var. multicostata. 



last four varieties 

 hitherto recorded 



have 

 from 



(These 

 been 

 the Shetland seas only.) 



compressa, Mont., and var. 



striata. The latter abundantly 

 diffused over the entire area. 



Venus exoleta, L. 



lincta, Putt. 



fasciata, Da Costa. 



casina, L. 



ovata, Penn. 



gallina, L. 



, var. laminosa, Mont. 



Tapes virgineus, L. 



Lucinopsis undata, Penn. 



Tellina fabula, Gron. 



pusilla, Pliil. 



Psammobia tellinella, Lam. 



ferroensis, Chem. 



Donax vittatus, Da Costa. 



, var. nitida. This va- 

 riety was obtained on the Dog- 

 ger bank, in 15 fathoms ; and 

 fully half of them were infested 

 with a pea-crab. 



