TESTACELLA. 31 



they are made from specimens in different states, and under diffe- 

 rent conditions. Our figure at the head of the genus is from a draw- 

 ing of an old and wrinkled individual, whilst that represented oppo- 

 site is from a young specimen in which the skin is expanded. The 

 animal is always of a light yellowish colour compared with T. 

 Maugii, which is of a darker mottled-brown, and the linear veining 

 is much interspersed with dark dots. The shell is small, characteris- 

 tically triangularly depressed towards the umbo. The principal 

 varieties of the species are those named T. scutulum, in which the 

 shell is more than usually attenuated in front, T. Companyonii which 

 has the shell large, and T. bisulcata in which the shell is so roughly 

 grown as to show two irregular grooves. M. Moquin-Tandon re- 

 marks that the animal of the last-named variety has generally a 

 smaller more elongated body of richer colour. Having preserved 

 and studied the character of living specimens sent to him from the 

 environs of Grasse, he came to the conclusion that they were scarcely 

 distinguishable from the original type of the species. 



MM. Gassies and Fisher adopt M. Dupuy's T. Campanyonii as 

 a distinct species, but they confess to not having seen it for a very 

 long time, and are unable to recall to their recollection its distinctive 

 characters. The grooved form, T. bisulcata, Eisso, they consider 

 ought to be maintained as a species, not only on account of a dif- 

 ference in the shell, but of the animal and of the form of the egg. 

 So far as the shell is concerned, the grooves appear to be mere va- 

 riations in the successive additions of growth. 



A great deal has been written on the ferocity with which the 

 Testacellce prey upon earthworms, and the manner in which they 

 will follow them in their subterranean windings. M. Gassies, who 

 kept a vivarium of Testacellce of all sizes and ages, gives a lively de- 

 scription of their cunning : — "When a Testacella has discovered the 

 prey on which it wishes to make a repast, it moves stealthily to one 

 side of the worm, with an indifference so complete, that one would 

 suppose it had not observed it and disdained it ; but suddenly it 

 turns, and while the worm is twisting to the right and to the left, 

 it lifts its head, withdraws its tentacles, dilates enormously its 

 mouth, and throws itself upon its prey, enfising it by a kind of 

 suction. Contortions of the worm are necessarily the result of the 

 wounds from the palate spines ; it wrestles, but in vain. Retained 

 by a multitude of barbs, its movements only serve to engage it more 

 and hasten its passage into the stomach of its voracious enemy." 



Originally a native of the Canary Islands, T. haliotidea has spread 



