40 NORMAN : ON THE MOLLUSCA OF BERGEN FIORDS. 



There has been the greatest confusion with respect to 

 the synonymy of this species, and I have therefore given it 

 rather fully. I dredged a single valve at Station 24; the 

 epidermis in a great measure remains on the shell, which is 

 in very much the same condition as are the valves of Leda 

 permda already mentioned as from Station 16. Yoldia a7'ctica 

 has however not yet been found living as far south as 

 Bergen, and therefore it will certainly for the present be 

 safer to regard this valve as fossil. Spirit-preserved speci- 

 mens are now before me which Captain Wiggens dredged on 

 "the west side of White Island, Kara Sea," when on his 

 interesting voyage, in 1876, to the mouth of the Yenisei. 



39. Yoldia tenuis, (Philippi). 



Nucida tenuis, Philippi. Enum. Mollus. Sicil, i., p. 65, 

 pi. v., fig. 9. 



Leda pygmcca, Jeffreys. Brit. ConchoL, ii., p. 154, pi. 

 xxix., fig. 5. 



This shell is well known to conchologists as Leda pygtJKza, 

 but Jeffreys has recently stated that it is not Miinster's 

 species and has therefore adopted Philippi's name ('Valorous' 

 Report, Proc. Royal Soc, xxv., 1876, p. 191). Besides the 

 typical form, which is generally diffused throughout the district 

 examined, a variety was met with in deeper water which seems 

 almost intermediate between Yoldia tenuis and Yoldia ahyssi- 

 cola, Torell (Spetsbergen Mollusca, p. 29, pi. i., fig. 4a-b). 



40. Yoldia lucida, Loven. 



Yoldia lucida, Loven. Index Mollus. Scand., 1845, p. 188, 



Leda lucida, Jeffreys. Brit. Conchol, v., p. 173, pi. c, 

 fig. I. 



Yoldia lucida, Reeve. Conchol. Icon., "^'Yoldia," 187 1, 

 pi. iv., fig. 17. 



Common in deep water down to 400 fathoms, on a 

 muddy bottom. 



J.C, ii., Feb., 1879 



