462 8BBEIC0BKIA. 



Prothorax slightly broader than long in the male, more transverse in the female, gradually narrowing 

 from the base, the sides rounded anteriorly; the hind angles moderately produced and strongly divergent 

 in the male, much shorter and not divergent in the female, acutely recurved at the tip in both sexes, not 

 carinate ; the surface densely and coarsely umbilicate-punctate, obsoletely canaliculate behind, and with a 

 sharp, transverse, sinuous carina before the base extending on either side to near the lateral margin, the 

 space between this and the base strongly declivous and more finely punctured. Elytra a little more than 

 three times the length of the prothorax, and of about the same width at the base, subparallel to the 

 middle in both sexes ; finely punctate-striate, the interstices flat, transversely rugulose and closely punc- 

 tured. Beneath closely punctured. Legs slender ; tarsi filiform, the basal joint of the hind pair about as 

 long as the following three joints united. 

 Length 6|-7|, breadth lf-2| millim. ( tf $ .) 



Hab. Mexico, Chilpancingo 4600 feet, and Omilteme 8000 feet, both in Guerrero 

 (H. H. Smith). 



A male from Chilpancingo and a female from Omilteme. This species may be at 

 once recognized by the long, sharp, sinuous, transverse carina near the base of the 

 thorax. The head appears bilobed in front, owing to the deep emargination in the 

 centre. In this respect the insect resembles the two Mexican species of Limonius, 

 but differs from them in the more elongate basal joint of the tarsi; it is therefore best 

 placed in Athous. 



ACANTHATHOUS. 



Head with a prominent, truncate frontal plate, and deeply excavate ; mandibles bifid ; antennae with the 

 second joint very small, the others elongate and subequal ; prothorax with exceedingly elongate, narrow, 

 divergent hind angles, which are recurved at the tip ; elytra broadly truncate at the apex, the outer apical 

 angle armed with a long sharp spine ; prosternum broad, with a broadly rounded, prominent chin-piece, 

 the process moderately long, horizontal, the sutures straight and single ; mesosternum depressed, the 

 cavity long and deep, the sides not thickened ; posterior coxa! plates harrow, gradually widening inwards ; 

 fifth ventral segment armed with a long spine at the apex; tarsi slender, the third joint widened and 

 sublamellate, the fourth very small, the basal joint as long as the following three joints united. 



The above characters are taken from a single species from the Pacific slope of 

 Guatemala. In the excessively elongate hind angles of the thorax, and the spinous 

 apex of the elytra and last ventral segment, it approaches the eastern genus Pachyderes, 

 belonging to the group Eudactylini, near which the insect ought to be placed, in 

 Dr. Candeze's opinion. The form of the front, the slender tarsi, with lamellate third 

 joint, the narrow coxal plates, &c, seem to me, however, to bring it much nearer 

 Athous. As a matter of fact, it only differs from Athous mexicanus and its allies in the 

 still more elongate hind angles of the thorax and the spinous apex of the body. 



1. Acanthathous pachyderoides. (Tab. XX. fig. 17, <$ .) 



Elongate, narrow, moderately convex, shining ; piceous or pitchy-brown, the head sometimes reddish-brown 

 in front; the elytra pitchy-brown or brown, with nearly the apical half indeterminately fulvous or 

 reddish-brown, this colour in some specimens extending forwards along the suture and on the outer part 

 of the disc ; the abdomen in great part fulvous or reddish-brown ; the antenna? and legs reddish-brown or 

 fusco-testaceous ; above and beneath sparsely clothed with fine decumbent fulvo-cinereous pubescence. 



