ORDER COLEOPTERA. 429 



Hydeophilus (properly so called), Geoff. Fab. Leach. 

 DytiscKs, Lin. 



Here the sternal spine is strongly prolonged behind. The 

 last articulation of the anterior tarsi of the males is dilated 

 in the manner of a triangular palette. The scutellum is 

 large These are the Hydrous of Dr. Leach. Zool. Misc. 

 III. p. 94. 



The larvae resemble a sort of worms, soft, with a conical 

 and elongated form, provided with six feet ; with the head 

 tolerably large, scaly, more convex underneath than above, 

 and armed with strong and crooked mandibles. They respire 

 by the posterior extremity of the body. They are very 

 voracious and injurious to ponds, by devouring the spawn. 



H. piceus. Fab. Oliv. Col. III. 39. 1. 1., is an inch and 

 a half long, oval, of a dark brown, polished, as it were, or 

 incrusted with a varnish, with the knob of the antennae 

 partly reddish, and some striae, not greatly marked, on the 

 elytra, the posterior extremity of which is rounded, exter- 

 nally, and prolonged into a little tooth at the external angle. 



It swims and flies remarkably well, but walks badly. Its 

 sternal point may sometimes wound when held in the hand 

 and allowed the liberty of moving. 



The anus of the female has two filaments, with which she 

 forms an ovoid shell, surmounted with a point, in the form 

 of an arched horn, and of a brown colour. Its external 

 tissue is a gummy paste, liquid at first, and subsequently 

 hardening and becoming impenetrable to water. Tlie eggs 

 which it envelopes are disposed there with symmetry, and 

 held together by a sort of white down. These eggs float on 

 the water. 



The larva is depressed, blackish, wrinkled, with the head 

 of a reddish brown, sniootii, round, and capable of being 

 turned backwards. This faculty affords it the means of 



