OKTHOSTETHUS.— AGEIOTES. 511 



Beneath thickly and finely, the prosternum coarsely and sparsely, punctured ; mesosternum subhorizontal, 

 moderately raised, V-shaped. 

 Length 23|, breadth 6| millim. 



Hab. Mexico, Pinos Altos in Chihuahua (Buchan- Hepburn). 



One worn example only of this peculiar species has been received. Differs from 

 all the other known members of the genus in the pectinate antennae in the male ; it 

 also has the sides of the mesosternum only moderately raised, and the elytra more 

 parellel than usual. The excavation of the front does not extend to the vertex, as 

 in 0. cavifrons. 



Group AGRIOTINI. 



AGRIOTES. 



Agriotes, Eschscholtz, in Them's Archiv, ii. 1, p. 34 (1829) ; Cand&ze, Monogr. Elat. iv. p. 358 ; 



Leconte, Trans. Am. Ent. Soc. xii. p. 15 (1884). 

 Ectinus, Eschscholtz, loc. cit. (part.). 

 Cataphagus, Stephens, 111. Brit. Ent., Mandib. iii. p. 185. 



This well-known genus contains about 120 described species, two-thirds of which 

 are from the Old World. Eighteen inhabit America north of Mexico, and a similar 

 number have been recorded from our region, whence many other species are now added, 

 chiefly from Mexico or Guatemala. Agriotes is apparently replaced in South America 

 and the Antilles * by Cosmesus, under which name Candeze has included various 

 heterogeneous forms f, and other allied genera. The Central-American species — many 

 of which are more brightly coloured than their northern allies, or have more definite 

 markings — are very local, few of them being common even to Mexico and Guatemala. 

 They all belong to Candeze's Section I. (A), in which the hind coxal plates are very 

 little widened inwards. Many of them are variable in colour (A. insolitus and others 

 differing sexually in this respect), or vary in the colour of the pubescence, the latter 

 sometimes being so arranged as to form spots on the thorax, or lines or vittae upon the 

 elytra. A. hirsutus differs from all the others in the semierect pubescence of the 

 upper surface. These insects are chiefly found at the roots of grass or low plants, often 

 upon the sandy banks of streams ; in sunny weather they may frequently be beaten 

 from herbage. 



The following key is added to assist in the identification of the Central-American 

 forms ; but as the chief characters upon which it is based gradually merge one into the 

 other, and are in some cases subject to variation in the same species, it must be used 

 with caution. 



* Agriotes australis, Fairm., from Punta Arenas, evidently belongs to a different genus ; A. guadulpensis, 

 Cand., from Guadeloupe I., is probably a Dolopius. 



f Some of the species of his Section II., such as the Colombian C. 7naurus and C. brevis, Cand., can hardly 

 be retained in it. 



