430 CLASS INSECTA. 



seizing the small shell-fish, which swim on the surface of 

 the water. Its back serves it as a sort of resting, and in 

 this sort of table it breaks the shells, and devours the ani- 

 mals which they enclose. The body of these larvae becomes 

 flaccid when they are taken up. They swim with facility, 

 and have, underneath the anus, two fleshy appendages, 

 which serve to sustain them on the surface of the water, the 

 head being under, when they come there to respire. Ac- 

 cording to M. Miger, who has furnished us with these obser- 

 vations, (Ann. du Mus. de THist. Nat. XIV. 441.) other 

 larvae of the hydrophili are deprived of these appendages, 

 and do not swim, and suspend themselves like the preceding. 

 The females of these species swim with difficulty, and carry 

 their eggs under the abdomen in a silken tissue ; but these 

 species belong to the last sub-genera of this tribe. 



That of the hydropMlus proper, of Dr. Leach, is com- 

 posed of species whose tarsi are identical in both sexes, and 

 not dilated, whose pectoral spine terminates with the poster- 

 num, and whose scutellum is proportionally smaller.* 



In all the following hydrophilii, the two intermediate 

 articulations of the knob of the antennae are perfectly trans- 

 verse, of a regular form, not prolonged in the manner of a 

 tooth, at one of their ends, and without a vacancy between 

 them. The last is obtuse or rounded at the end. The 

 breast presents neither keel nor spine. The tarsi are much 

 less adapted for swimming, little or not at all ciliate, and 

 terminated b}?^ large crooks equal and simple. 



Those whose maxillary palpi are much longer than the 

 antennas, with the last articulation shorter than the pre- 



• Refer to the Hydroiis of Dr. Leach, beside piceus, the following 

 species of Fabricius : ater, olivaceus, ruflpes, &c. Those which the latter 

 names carabdides, elUpticus, &c. are the hydrophilii proper of the English 

 naturalist. 



