JOURNAL OF CONCHOLOGY. 241 



ADDITIONS TO 'BRITISH CONCHOLOGY.' 



By J. T. MARSHALL. 



(Read before the Conchological Societj- March i, 1893). 



In view of the publication of a new edition of Mr. Somer- 

 ville's List of British Marine Shells in the near future, it is 

 desirable to place on record descriptions of such new species 

 and varieties as have been found since that gentleman issued 

 his l>ist in 1886, the best of its kind published up to that date. 

 Some of the varieties appeared in that List as MS., and, while 

 a few of them have since been described, there are still some 

 that await description, together with other varieties and a few 

 species which do not appear in that List. 



In introducing doubtful . species as British, I think it best 

 to state simply the grounds on which they are proposed, and 

 leave it to individual collectors to follow their own discretion 

 as to adopting or rejecting them. I do not presume to impose 

 my dicta upon any one. 



I do not propose to include any of the species obtained in 

 the ' Lightning,' ' Porcupine,' and other deep-sea Government 

 expeditions, except where there is evidence of the shell having 

 been also found in private dredgings actually on our coasts, 

 though Jeffreys says of the ' Lightning ' cruise — ' Some of the 

 localities may be considered British, being much nearer Scot- 

 land than Faroe.' For although many of the ' Porcupine' 

 dredgings were off our coasts, they were mostly at depths which 

 preclude their ever being obtainable by private enterprise, and 

 it is almost useless to load our List with names of species that 

 may never be acquired by collectors. 



In a second paper I propose to enumerate the changes in 

 nomeuclalure which have become absolutely necessary. These will 

 be few, for it is to me an important consideration how far we 

 ought to conserve our standard authorities while making gradual 



