HARD WICKE'S SCIENCE-GOSSIP. 



25 



NOTES ON THE CONCHOLOGICAL SOCIETY'S NEW LIST 

 OF BRITISH MOLLUSCA. 



By T. D. A. COCKERELL. 



]_Co?itinucd Jrom p. 16.] 



ODIFICA TIONS 

 of a racial charac- 

 ter, continuously 

 inherited, itidepen- 

 dently of the nor- 

 mal form. 



It is hardly ne- 

 cessary to dwell 

 on these, further 

 than to remark 

 that they are often 

 so by virtue of 

 isolation, and if 

 brought into con- 

 nection with the 

 normal form would 

 speedily be re- 

 duced to the rank 

 of mutations by 

 intercrossing, if 

 their characters did 

 not become obliterated. It is for this reason that we 

 do not call them true species, but they are, of course, 

 a further step towards the formation of species. 



So much for preliminary remarks ; I will now pro- 

 ceed to notice various points in the list which seem to 

 call for criticism or comment, omitting mere matters 

 of opinion, and also numerous matters which I do not 

 feel competent to discuss, without more research than 

 I have time for. 



1. Arion ater, var. bicolor ; why credited to Roe- 

 buck, instead of Moquin-Tandon ? 



2. A. ater, var. nigrescens (Razoumouskii) is 

 omitted, though hitherto accepted as valid by Mr. 

 Roebuck, and the same remark applies to vars. 

 pallescens and succineus. 



3. A. ater, v. cinerea ( = cinerasceus) is omitted, 

 though described as new by Mr. Roebuck in " Natu- 

 ralist," 1888, p. 284, from a Nottingham specimen. 



No. 338. — February 1893. 



4. Limax maximus, var. cinerea, Moq., is really 

 Midler's L. cinereus a, which is the same as cinereo- 

 niger. The English v. cinerea of Roebuck is doubt- 

 less a different thing, and correctly referred to 

 maximus. 



5. L.flaviis, where is Mr. Roebuck's var. griseus.? 

 Is it considered a synonym of var. maculatus, Kal. ? 

 It should be mentioned that Moquin-Tandon's macu- 

 latus is different from Kaleniczenko's, and being of 

 more recent date, stands in need of a new name. It 

 may be called nigromaculatus, being brown with black 

 spots. The varieties tigrinus and colubrinus of Pini 

 are closely allied, and all three were found by Pini at 

 Esino. 



6. Agriolimax agrestis, var. flans, which is 

 dropped, is certainly not more distinct than several 

 mutations which have not yet been named. 



7. A. agrestis, var, albida, as usually accepted in 

 England, is really var. alba, Ckll. There has been 

 some difference of opinion as to the true var. albidus, 

 but at all events, it seems not to be an albino, like 

 alba. 



8. Hyalinia cellaria, var. compacta, Jeff., omitted 

 from the list, has been regarded as identical with the 

 earlier named var. silvatica, Morch ; while var. com- 

 planata, according to Westerlund, is not separable 

 from the type. 



9. Helix aspersa, var. grisea. Why is this omitted ? 

 The name was an ill-chosen one, but the variety, as 

 generally recognised, is quite a local race in some 

 districts. 



10. Helix nemoralis. The var. caryiea, introduced 

 some years ago by Messrs. Roebuck and Taylor, was 

 not defined, and now it disappears without having 

 given a proper account of itself. The only descrip- 

 tion of it I have seen is that given by Mr. Williams 

 in 1SS9. 



11. Helix hortejisis, var. pallida, which is omitted, 

 is to some extent a geographical race, according to 



c 



