COLEOPTERA. 5 1 1 



Desmarest resumed these observations. He provided himself, at the 

 Veterinary College of Alfort, with a number of shells of the Helix 

 filled with the same larvae. He saw come out of them, not only 

 Cochleoctoni, but also Drill, and he watched their coupling. It was 

 then proved, by this unanswerable argument, that these two insects, 

 so unlike each other, belong to the same species. 



The larva of the Drilus flavescens fixes itself upon the shell of the 

 snail by a sort of sucker, like a leech. Little by little it slips in 

 between the mollusc and its house, and devours it entirely. To 



Fig. 552. Jumping organ of the Elater, 

 seen sideways. 



Fig. 551. Jumping organ Fig. 553. Larva of the Elater. 



of the Elater. 



change into a pupa, it shuts up the entrance to the shell with its old 

 skin ; and when arrived at the perfect state, quits the shell which 

 served it as a temporary dwelling. The females of the Drilus 

 flavescens take refuge under stones and dry leaves, or crawl slowly 

 along the ground ; whilst the males, which fly with great ease, are 

 on the plants and brushwood. These insects are not rare in the 

 environs of Paris. M. H. Lucas has observed, in Algeria, near to 

 Oran, another curious species, the Drilus Mauritanicus. The lafrva 

 of this insect lives at the expense of the animal of the Cydostoma 

 Volzianum, which closes the entrance to its shell with a covering of 

 some calcareous substance. It fixes itself on the edge of the shell, 

 with the aid of its sucker, and directs its strong mandibles to the side 

 on which the snail is obliged to raise the covering, either to breathe 

 the air or to walk. In this position it has the patience to wait for 



