COCKERELL AND COLLINGE : CHECK-LIST OF SLUGS. 2 1? 



ones are occasionally found in England. All the species 

 of the gagaies group are very closely allied, and the validity 

 of some IS doubtful ; but they can hardly be studied in 

 a satisfactory manner without much larger collections than 

 are at present available in museums. Meanwhile, it seems 

 best to keep them distinct, and to treat somewhat cautiously 

 assertions of identity which are not backed by adequate 

 comparison of specimens.'' 

 91 /■ pdllida. I merely include this name as it has been published; 



it does not represent any distinct variety. 

 1 06. A. pallidula^ Ckll., is a small form, distinguished from the 

 young of sozverbii by its colour, its transparency, its high 

 acute keel, and its non-attenuate tail. A. cristata, Kal., 

 as figured by its author, is pale reddish-ochre, head and 

 neck blackish, no sulcus visible on mantle — thus unlike 

 pallidula. But Dr. Simroth has lately figured as cristata 

 a slug w-hich seems so like pallidula that they may well be 

 the same thing. Hence, assuming that Dr. Simroth has 

 correctly identified his slug, and that Kaleniczenko's figure 

 was somewhat misleading, I place pallidula as a doubtful 

 synonym of cristata. 

 113. = Aspidoporus Umax, Fitz. 



Agrioliniax, 1868. This is a good test case for the law of 

 priority, all the following names being prior to it. 



(i.) Deroceras, 1820. There can be little doubt that 



D. gracilis, Raf., w^as A. cauipestris, Binn., but the 



description was inaccurate. 



(2.) Liiiiacelius, 182 1, as quoted by Kreglinger, may be 



a mistake. Limacellus, as known to me in Ferussac's 



writings, is Blainville's genus — a totally different thing. 



(3.) Krynickia, 1839 (afterwards called Kryfiickillus, and 



also Megaspis), has been used for the lievis group of 



Agrioliniax, but I do not see how this restriction can 



be justified. However, it included some species of 



Agrioli)uax. 



(4.) Malino, 1855, was founded on A. lombricoides — 



a true Agriolimax — yet its author was under a mis- 



'I have elsewhere (Conch. 1892, ii. p. 92) pointed out that in my opinion A. plumbea is but 

 a colour variation of .^. gagates. I fail to see any reason whatever why it should be regarded as 

 specifically distinct from A. gagates any more than any of the other colour varieties. The 

 anatomical evidence for the specific identity of a number of the gagates group is practically «//, * 

 and mal.^cologists will do well to recognise only such whose anatomy has been fully described 

 and figured. The constant splitting up of a species into subspecies, varieties, &.C., is a practice 

 I have little patience with, and in a difficult genus like AmaUa it is only adding confusion to an 

 already complicated study, and heaping up difficulties in the way of future workers. — W. E. C. 



