ARTH ROCORYNUS.—MECISTOCORYNUS. oll 
of the anterior legs of the male. The asymmetrically dilated basal joints of the 
anterior tarsi in this sex, the transverse whitish patch at the base of the elytra, &c., 
distinguish the present species from the following one. In some of the females from 
Panzos and San Isidro the rostrum is almost smooth. 
2. Arthrocorynus dotatus, sp. n. (Tab. XXV. figg. 13, ¢; 134, anterior 
tarsus, 3 .) 
Gasterocercus dorsalis, Chevr. in litt. 
Very like A. brachialis, but with the vestiture of the upper surface brown or fulvous, variegated with black, 
the prothorax with a short streak in the middle at the base, and sometimes another at the apex, and the 
elytra each with an irregular transverse more or less distinct patch at about the middle of the disc, white. 
Elytra not transversely depressed in the scutellar region, with all the interstices convex and seriato- 
granulate. Anterior legs of the ¢ very elongate, and their tibiew denticulate on the outer face, in well- 
developed specimens, sometimes very little longer than in the @ and with the tibie unarmed; the tooth 
on the anterior femora very small, and the two basal joints of the anterior tarsi normally formed, in 
the 3. 
Length 63-104, breadth 3-5 millim. (¢ 9.) 
Hab. Mxxico, Orizaba (Sallé) ; Guaremata, San Isidro, Guatemala City (Champion) ; 
Panama, Bugaba (Champion). 
Ten specimens, seven of which are from Mexico. The variation in the development 
of the anterior legs of the male is greater than in A. brachialis; examples of this sex, 
however, are always distinguishable by the hairy anterior tarsi and the small tooth of 
the anterior femora. The specific name dorsalis has already been used in at least two 
of the allied genera. 
MECISTOCORYNUS, gen. nov. 
Rostrum rather slender, about as long as the head and prothorax, a little widened at the base ; eyes very 
large, subapproximate ; antennz inserted at the middle of the rostrum in the ¢, and nearer the base in 
the 9, the funiculus 7-jointed, 2 elongate in the ¢, 5-7 transverse, the club subcylindrical, very elongate, 
pubescent, the sutures oblique, the two basal joints tubulate and extending far forwards on the lower 
face; prothorax broader in the ¢ than in the ?, with feebly developed ocular lobes, the vibrisse short, 
the base almost straight; scutellum small, transverse; elytra not (¢ ) or very little (2) wider than the 
prothorax, with nine rows of punctures and also a short outer row at the base ; prosternum with a very 
deep rostral canal, the latter reaching to about the middle of the intermediate coxe, the mesosternum 
horseshoe-shaped ; metasternum rather long, the episterna broad ; ventral segments 3 and 4 each slightly 
shorter than 2, the first suture curved; legs comparatively short in the Q, longer in the d, the 
anterior pair greatly elongated and modified in this sex ; femora feebly clavate in the 9, sublinear in the 
dg, unidentate (the anterior pair of the g excepted); tibie unguiculate at the outer apical angle, the 
anterior pair of the ¢ very long, sinuous, denticulate and suleate within, and sharply mucronate at the 
inner apical angle ; anterior tarsi of the ¢ (fig. 14 c) with joint 1 nearly twice as long as the others united, 
and also dilated on the inner side near the base and at the apex, sulecate beneath, without projecting 
hairs ; body oblong-ovate, squamose. 
This genus includes a single species from Central America. It approaches Macro- 
merus, Cylindrocorynus, and Celosternus in one or other of its characters. The male is 
a very remarkable insect. 
