288 THE ZOOLOGIST. 



end of the annelid, and the Hampstead specimen had its victim 

 fast by the first few segments. Gassies and Fischer figure an 

 example of T. maugei with its contracted end in contact with the 

 middle of a worm, but there is no evidence that the latter is being 

 held by anything, and it cannot well be imagined how a really 

 large worm could be swallowed if seized in the centre, as two 

 thicknesses of it would have to be drawn in at once. 



Another point there is which is dependent on the comparative 

 size of the worm — namely, whether it can all be swallowed at 

 once — and indeed if a worm were caught that could not be 

 accommodated within the slug, part of it might well be digested 

 before the rest, which would remain connected with it, but outside 

 the devourer. 



It will be seen that Testacella is particularly well adapted 

 for catching its prey should it meet them in the mouth or other 

 portion of their tunnels. The slug on coming in contact with 

 the head of an advancing earthworm, appearing above ground or 

 what not, would contract, and shrinking back would entirely 

 block the way with its now swollen body. The worm in 

 endeavouring to proceed with more certainty than in the experi- 

 ments, would continue to irritate the surface of the slug, seeking 

 the groove above the slug's mouth — in some cases small worms 

 actually managed to force their prostomia into the oral aperture — 

 and would be caught in the grip of the radula as it was shot 

 out and held securely, the slug maintaining by its broadened 

 body a firm hold on the walls of the burrow. This method of 

 procedure would not, of course, prevent the Testacella from 

 attempting to secure worms in the open, its stealthy movements 

 not alarming the latter in any way, but it would not be so certain 

 of a meal, as the chances of a successful hit with the radula are 

 by no means so great. 



As already pointed out, Sowerby described Testacella scutulum 

 as a distinct species, but it has been generally considered to be 

 merely a variety of T. haliotoidea, and perhaps some good reasons 

 for now treating it as a species ought to be forthcoming. 



Mr.J.W. Taylor,* in 1888, states that Mr. Charles Ashford's 

 researches on the anatomy in 1885 leave no doubt that T. 

 scutulum is distinct from T. Iialiotoidea, but that it approaches 



* " On the Specific Distinctness and Geographical Distribution of Testa- 

 cella scutulum" Journ. Conchol. 1888, p. 837* 





