COLEOPTERA. 325 



Noteiius, Clairv. 



No scutel; tarsi consisting of five distinct joints, and the two first 

 of the four anterior dilated in the males, forming an elongated pa- 

 lette; first joint of the two anterior tarsi covered hy a broad lamini- 

 form spur, the part of the pectus bearing the last legs with a deep 

 groove on each side(l). 



The others have but ten distinct joints in their antennae; their ex- 

 terior palpi are fusiform, or have a more slender termination taper- 

 ing to a point, and the base of the posterior legs is covered with a 

 large shield. 



The body is convex and ovoid underneath, as in Hygrobia; but 

 there is no scutel, and all the tarsi are filiform, composed of five al- 

 most cylindrical joints, and have nearly the same form in both sexes. 

 They are the 



Haliplus, Lat. Hoplitus, Clair. Cnemidotus, Illig.(2) 



The second genus of the Hydrocanthari, or the 



Gyrinus, Lin. 



Comprises those in which the antennae are clavate and shorter 

 than the head; the two first legs are long and project like arms; the 

 remaining four are compressed, wide, and pinnate. There are four 

 eyes. 



The body is oval and usually very glossy. The second joint of 

 the antennae, which are inserted in a cavity before the eyes, is pro- 

 longed exteriorly in the form of an auricle, and the following 

 joints(3) are very short, crowded, and united in one almost fusiform 

 and slightly curved mass. The head is sunk in the thorax almost 

 to the eyes, which are large, and divided by a border, in such a way 

 that two are above and two underneath. The labrum is rounded 

 and strongly ciliated before. The palpi are very small, and the in- 

 terior of those attached to the maxillae are wanting, or are not de- 

 veloped in several, and particularly the larger species. The thorax 

 is short and transversal. The elytra are obtuse and truncated at 

 their posterior extremity, leaving the anus exposed, which ends in a 



(1) Dytiscus crassicornis, Fab.; Clairv., Entom. Helv., II, xxxii. 



(2) The Dytisci fulvus, impressus and obliquus, Fab. See Latr., Gener. Crust. 

 et Insect., I, p. 234; Clairv., Entom. Helv., II, genus Hoplitus, XXXI; Fanz., Ind. 

 Entom., genus id., and Schcenerr, Synonym. Insect. II, genus Cnemidotus. 

 [American species, Hal. 12-punctatus, triopsis, &c. Am- Ed.} 



(3] But seven are distinctly visible, the first and last of which are the longest. 



