GENUS TESTACELLA. a) 
They are nocturnal animals, usually remaining beneath the surface of the 
soil during the day, preferring the rich, well- manured lands in which their 
prey is plentiful, and in this country, according to Mr. E. J. Lowe, are 
found from sea level up to an altitude of 530 feet, and although reaching a 
greater altitude in France, yet Fischer records that they do not attain an 
altitude of 3,250 feet in Auvergne. Although usually living only a few 
inches below the surface, they vary the depth im accordance with the-mois- 
ture of the ground and the consequent motions of the earthworms, but also 
come forth at nightfall when the earthworms also emerge from their bur- 
rows ; the worm “when seized by the Testucella instantly retracts itself 
within its tunnel by the aid of its circlets of bristles, dragging with it the 
Testacella, which attenuates itself sufficiently to allow this to be done. 
The saturation of the ground due to the rains so prevalent in spring and 
late autumn is very prejudici al to the Testucelle, driving them from their 
subterranean retreats to the surface, where they seek to hide during the 
day beneath stones, rubbish, or in other places frequented by worms. 
In cold and dry weather, and when preparing for hibernation, they retire 
deeply into the earth, contracting their bodies and enveloping their hinder 
extremity within the extended mantle, ensconcing themselves each within a 
small and firm earth-chamber, which is cemented together by their colour- 
less and somewhat viscid mucus, and is smooth and glistening inside, but 
externally bears some resemblance to the cocoon of a “puss” moth. 
Enemies.—<According to the testimony of Mr. Miller and Miss Mar- 
shall, earthworms will destroy young Testacellw, and Mrs. Falloon informs 
me that a very small wireworm also preys upon them. 
Geographical Distribution.— 7¢stacedlw is entirely a western palie-~ 
arctic group, and the distribution of the constituent species is strikingly in 
harmony with the relative simplicity or complexity of the internal structure 
of the animal, the more primitive of the species being confined to the 
vicinity of the western sea board, while the more highly or eanized forms have 
a more eastern range. ‘I'he genus is replaced in eastern “and south-eastern 
Kurope and the western Asiatic region by Daudeburdia, a group of preda- 
cious snails with close affinities to Testucella. 
The so-called West Indian Testaucellw are more properly referred to Omu- 
lonyx, a genus of Succineide, in which the shell has undergone a somewhat 
parallel course of degeneration. 
Geological History.—Fossil species of Testucella have been recorded 
from various localities in the Middle and Upper Miocene, the Pliocene, 
Pleistocene, and Holocene strata of continental Hurope. 
Fic. 6.—T7. maugei devouring a worm. 
