388 
Mr. T. D. A. Cockerell’s Notes on Slugs . 
It is interesting to be able to redescribe this slug, as it has 
been a lost species, not recognized by subsequent authors. 
It is surely not an Arion , and it may represent a new genus, 
unless it belongs to Morch’s Oopelta , with which it seems to 
agree externally so far as generic characters go. But until 
the jaw and lingual dentition of A . atcrrimus are known it 
will be impossible to be certain of its proper position. 
Ariunculus Moreleti (Hesse). 
Length 13 millim., breadth millim. Head dark brown. 
Mantle dark brown, faintly mottled with black lateral bands, 
bordered above by pale bands, and continuous with those on 
body ; respiratory orifice a little anterior to middle. Body 
pale grey at sides, with dark lateral bands and dark sub- 
dorsal bands, four in all, leaving pale dorsal and subdorsal 
narrow bands between them. Sole broad and grey. 
Described from a specimen kindly sent to me by Mr. J. H. 
Ponsonby, collected at Tangier some years ago. It differs a 
little from the original description, but is evidently the same 
species. 
Pollonera has recently placed this species in Geomalacus , 
subg. Letourneuxia. 
Testacella albida. 
1885. Testacella haliotidea , v. scutulum (pars), Taylor and Roebuck, 
Journ. of Conch, iv. April, p. 320. ( Hab . Gibraltar.) 
1885. Testacella haliotidea , v. scutulum , subv. albida , Cockerell, Sci. 
Goss. October, p. 225. {Hab. Gibraltar.) 
1887. Testacella , sp., Ponsonby, Journ. of Conch, v. July, p. 195. {Hab. 
Gibraltar.) 
1888. Testacella , probably haliotidea , Taylor, Journ. of Conch, v. July, 
p. 346. {Hab. Gibraltar.) 
1888. Testacella , sp., Pollonera, Boll. Mus. Zool. An. Comp. Torino, 
p. 6, figs. 10, 11. {Hab. Olot, Spain.) 
The dried type of T . albida , collected by the Rev. J. W. 
Horsley at Gibraltar, is as follows : — 
Length 15J millim.; sole 3 millim. broad; dorsal longi- 
tudinal grooves about 2§ millim. apart, oblique grooves well 
marked. Sole separated from body by a groove and with 
transverse grooves at intervals, well marked at sides. 
Nucleus of the shell gone (broken or eroded). Shell pale 
horn, growth-ridges strong. Length of shell 4 millim. 
The other white Testacella recorded from Spain (by Pollo- 
nera) is placed here, although the Gibraltar shell is narrower 
anteriorly than Pollonera’s figure. It is not very likely that 
