334 Mr. T. D. A. CockerelFs Notes on Slugs. 



certain imported Mammals in the Falkland Islands ; but in 

 New Zealand there are native species, found nowhere else, 

 which can hardly have sprung from ancestors brought there 

 by human means. 



The existence of peculiar species in New Zealand (and 

 others reported from Tasmania) thus throws some doubt on 

 the otherwise natural supposition that the insular, South 

 African, and Western American forms of A. gagates were 

 imported from Europe ; and when we consider the very out- 

 of-the-way localities in which they have been found, the 

 theory of human accidental interference seems still less uni- 

 versally applicable. 



Where, however, we find islands with no peculiar species 

 of slugs, but with such cosmopolitan forms as Amalla gagates, 

 Agriolimax agrestis, and Limax flavus, the probability that 

 these have been introduced becomes practically a certainty, 

 and " new species " desciubed in the faunse of oceanic islands 

 must be looked on with suspicion when they belong to Limax, 

 Amalia, or Agriolimax. 



i. Madeira. 



Amalia (gagates subsp.) drymonia (Bourg.). 



Bourguignat appears never to have seen the various slugs 

 he named drymonius, abrostolus, calendymus, and polyptyelus 

 in Amen. Mai. vol. ii. (1859), and their characters are prob- 

 ably for the most part imaginary. Amalia drymonia, founded 

 on Albers's account of the Madeiran A. gagates, is allied to 

 the form Benoiti, to judge from the description ; but whether 

 any white-keeled Amalia really exists in Madeira seems at 

 least questionable. The figures of the Madeiran and Canarian 

 slugs given by Albers and d'Orbigny are so evidently coloured 

 without serious regard to truth that species founded upon them 

 cannot possibly be accepted as valid unless specimens 

 resembling the figures should be found. 



Amalia gagates, var. nov. maderensis. 



Length (in alcohol) 14 millim., uniform dark brown, 

 including foot; mantle blackish. The colour suggests A. 

 fuliginosa. 



Very near gagates, from which it differs only in colour, so 

 far as I can see. Middle zone of sole more than twice as 

 broad as either lateral zone ; sulcations on sole as in gagates. 

 Sole dark brown, unicolorous. Mantle oval. Keel not 

 strong. 



Madeira [Mr. Mason) ; one specimen in the British Museum. 



