390 Messrs. Leckenby and Marshall 



EXPLANATION OF PLATE XIII. 



Fig. 1, Cahjptostoma Hardiii a, magnified view, from above; b, ditto, 

 underside ; c, ditto, in profile ; d, fore part more enlarged, 

 showing the eyes ; e, tarsus of leg of first pair ; /, natural 

 length. 



Fig. 2. Westwoodia obtecta : a, magnified view, from above ; b, ditto, in 

 profile ; c, underside, with legs truncated ; d, oval cavity con- 

 taining the mouth-parts, highly magnified ; e, leg of first pair ; 

 f, terminal claws of ditto ; g, natural length. 



Fig. 3. Cyphophthahnus cimiciformis : a, magnified view, from above and 

 behind ; b, ditto, in profile, with legs and palpi partly removed ; 

 c, ditto, underside ; d, leg of fourth pair ; e, tarsus of leg of first 

 pair ; f, natural length. 



LIV. — North-Sea Dredging. By John Leckenby, F.G.S., 

 and J. T. Marshall. 



The Dogger bank and its slopes have always been considered 

 (and deservedly) the El Dorado of conchologists ; and having 

 made three dredging-crnises there, twice in 1868 and again in 

 August of this year, with results satisfactory to ourselves, and, 

 we hope, of interest to conchologists generally, we are induced 

 to publish a list of those species which have occurred to us, 

 premising that only those are enumerated which have been 

 met with out at sea, between 20 and 90 miles from land, in 

 depths ranging from 7 to 50 fathoms. 



The Dogger bank occupies the centre of the North Sea, is 

 200 miles in length and from 30 to 50 broad, commencing 

 about 60 miles from the Yorkshire coast, and intermediate 

 between the shores of England and Denmark. Its average 

 depth is 15 fathoms, though in a few places it is only 7, with 

 pits of deep water here and there, the most notable of which 

 are the Great and Little Silver Pits and the Well Pit. The 

 Bank gradually slopes into deeper water ranging from 40 to 

 50 fathoms ; and it is here that the rarer species of Fust &c. 

 are found, the fauna on the Bank itself corresponding to that 

 found in shallow water near the shore. 



Our dredgings were carried on in a cutter of 45 tons, chartered 

 at Scarborough, with a crew of five Naval-Reserve men. 



We have adopted the nomenclature of Jeffreys's ' British 

 Conchology,' and have marked with an asterisk those which 

 have not been before recorded. 



Scarborough, October 1875. 



