126 



Mesocanthicus, from /necros and clkolvOikos, spinosus, 

 and the last sub-genus has the apex of the elytra 

 conspicuously marked by four spines, and is con- 

 sequently named Tetracanthicus. Three species 

 in my collection are from Tropical Africa, it will 

 also probably occur in the warmer parts of Asia. 

 The two former genera seem widely dispersed 

 throughout the world, inhabiting both the Old and 

 New Continent. I possess among my aquatics three 

 species of Hydrous belonging to Australia. The 

 above insects weave a sort of coccoon, in which 

 the ova are deposited ; as to substance it appears to 

 combine the paper of the Wasp, with the silk of the 

 Bombyx, when submerged beneath the water for 

 many hours the coccoon remains nearly unaltered 

 by the moisture, a secretion produced by the insect 

 probably resists the action of water upon it. 



2. Hydrophilus of Authors. 



Sp. 2. Caraboides. — For figures of the Coccoon 

 and Larvae of Hydrous and Hydrophilus, the 

 student may consult Rosel's Insect. Belust. Vol. 2. 

 Tab. 41 ; and also Mr. Westwood's Introduction 

 to the Modern Classification of Insects, Vid. Part 

 3. p. 121. fig. 8, &c. 



