COLEOPTERA. 397 



themselves like those of which we have been speaking. The 

 females of these species swim with difficulty, and carry their 

 ova under the abdomen enclosed in a silken web; but these spe- 

 cies belong to the last subgenera of this tribe. 

 The Hydrophilus proper of Leach consists of species in which 

 the tarsi are identical in both sexes, and not dilated, the pectoral 

 spine terminates with the poststernum, and in which the scutel is 

 proportionally smaller(l). 



In all the following Hydrophilii, the two intermediate joints of 

 the antennal club are exactly transversal, of a regular form, not pro- 

 longed into a tooth at either extremity, and without any space be- 

 tween them; the last is obtuse or rounded at the end. The pectus 

 exhibits neither carina nor spine. The tarsi are less, or not at all 

 fitted for natation, but slightly or not ciliated, and terminated by 

 large, equal, and simple hooks. 



Those in which the maxillary palpi are hardly longer than the an- 

 tennae, with the last joint shorter than the preceding one, and cylin- 

 drical, in which the body is low, and the elytra are truncated at the 

 extremity, or very obtuse, form the genus 



LiMNEBius, Leach(2). 



Those, in which the maxillary palpi are hardly longer than the 

 antennae, with the last joint as long as the preceding one or longer, 

 and almost oval, and in which the body is convex, are comprised by 

 the same English savant in two genera. In one of them, the 



.Hydrobius, Leach, 



The eyes are depressed or but slightly convex; the anterior extre- 

 mity of the head is not abruptly narrowed, and the base of the tho- 

 rax is as wide as that of the elytra(3). In 



Berosus, Leach, 



On the contrary, the eyes are very prominent, the anterior extre- 

 mity of the head is narrowed abruptly, and the base of the thorax is 

 narrower than that of the elytra. The body is very convex(4). 



(1) To the HxDRous, Leach, besides the piceiis, refer the following species of 

 Fabricius: the aier, oUvaceus, rufipes, &c. Those, which tlie latter calls caraboides, 

 dlipticus, &c. , are Hydrophlli properly so called of Leach. 



(2) H. griseus, truncatellus. Fab. 



(3) The Hydrobii scarabseoides, melcmocephalus, orbicularis, &c. 



(4) H, luridus, Fab. 



