COCKERELL AND COLLINGE : CHECK-LIST OF SLUGS. 57 



which are so prominent in the present list. I will only mention 

 a single example to show the utter absurdity of such a method of 

 treatment. The genus Amalia has been thrown into the greatest 

 confusion and chaos, so many are the species made out of the slight 

 anatomical variations and the many colour variations of four or five 

 species. Professor Cockerell warns malacologists re confident 

 assertions, the admission of errors and the consideration of others' 

 views, all of which are very apt and opportune, but when a case is 

 brought to the test, and anatomical evidence of the most convincing 

 and undeniable character from the ablest malacological anatomist 

 living, is advanced to disprove the specific identity of such a variety 

 as cinereo-niger of Z. inaximus, he writes : — " I have never been at 

 a loss to identify cinereo-niger by external marks." 



Coming to the Arionidce, a family I am particularly interested in, 

 there is much that I cannot agree with, re A. ater, ncfiis, and empiri- 

 corum. Professor Cockerell seems to have overlooked the fact that 

 because Linne thought that Lister's species was identical with his, or 

 vice versa, it does not at all prove that either were right. My view — 

 possibly I am quite wrong — is that Linne described an Arion which 

 he termed ater — I am omitting any question as to genera— a species 

 which seems to be limited to the Scandinavian region ; he also 

 described an A. rufus, which is probably but a variety of A. ater} 

 Various other European authors later described a large black Arion 

 or varieties of it. The best description, however, about which there 

 can be no doubt as to the species, is that of Ferus.sac's. He gave 

 the name einpiricoriun to this slug. Moquin-Tandon named the red 

 variety ruber, which, however, must give way to Kaleniczenko's var. 

 lamarckii (if the description is good), which is the same thing, and 

 there the matter ends. 



What Professor Cockerell is trying to prove respecting the 

 varieties bocagei, sukatus, and viu/ieri I really fail to see. First he 

 endeavours to prove that sukatus is something for which there is no 

 evidence whatever, and classes bocagei as a variety of it, whereas 

 Simroth, its author, classed it as a variety of empiricorum. He next 

 suggests to class bocagei n.s a subvariety o( n/u//eri and finally concludes 

 " that bocagei is the mu/kri-\ike form of sti/catus" Simroth states that 

 sukatus is identical with empiricorum, and even Pollonera advances 

 little or nothing in support of its identity as a species. If there is any 

 evidence — I have not the original description by me — for supposing 

 Miiller's variety is identical with Simroth's, then the former must 

 have priority, and sukatus should remain as a distinct variety of 

 empiricorutn, unless we place the three unnamed minor forms I have 

 described, all under one name. It seems to me that Moquin- 



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