510 RHYNCHOPHORA. 
ARTHROCORYNUS. 
Rostrum stout, rather short, flattened at the tip, a little widened at the base and apex, the scrobes deep and 
descending to the lower limit of the eyes; eyes very large, finely facetted, widely separated; antenne 
inserted at about the middle of the rostrum in both sexes, the funiculus 7-jointed, 2 a little longer than 1, 
the club ovate, acuminate, with deep transverse sutures; prothorax broader than long, narrowly and 
arcuately produced at the apex, the base very deeply bisinuate, the median lobe truncate, the hind angles 
broadly and obliquely truncate and received into the excavate base of the elytra, the ocular lobes well- 
developed ; scutellum rounded, rather small; elytra not or very little wider than the prothorax, with 
nine rows of punctures and also a short outer row at the base, the humeri sharply produced in front ; 
prosternum with a very deep rostral canal; mesosternum raised, broad, extending forwards, arcuately 
emarginate in front; metasternum rather short, the episterna moderately broad; ventral segments 
3 and 4 each a little shorter than 2; legs rugosely punctate, comparatively short in the 9, longer in the 
3, the anterior pair (except in poorly-developed specimens) greatly elongated in the latter sex; femora 
feebly clavate and unidentate, the anterior pair in the ¢ very long, linear, slightly curved inwards, 
and feebly dentate ; tibia carinate, unguiculate at the outer apical angle, the anterior pair in the ¢ very 
long and sinuously bowed inwards ; tarsi with joint 3 strongly bilobed, the anterior pair of the g clothed 
with long, projecting hairs, and sometimes with joints 1 and 2 asymmetrically formed, the claws simple ; 
body oblong-ovate, robust, squamose. 
Two species are referred to this genus, both of which have long been known under 
MSS. names of Chevrolat or Jekel. They agree with Gasterocercus in the form of the 
mesosternum, but can hardly be included in it, even in the widest sense, on account 
of the trilobate base of the prothorax, the elongated anterior legs of the male, the 
sublinear anterior femora in this sex, the less flattened rostrum, &c. The sculpture of 
the rostrum is variable in the females. 
1. Arthrocorynus brachialis, sp. n. (Tab. XXV. fige. 11,lla, ¢; 113, an- 
terior tarsus, ¢; 12, anterior leg, 2.) 
Gasterocercus brachialis, Jekel, in litt.’. 
Gasterocercus mexicanus, Chevr. in litt.’. 
Black, variegated with fulvous, cinereous or white, and blackish scales, the whitish scales condensed into three 
patches at the base of the prothorax, and a broad, transverse, scutellar patch and a subapical fascia on the 
elytra ; the vestiture of the under surface and legs sparser, the latter subannulate. Head densely, 
rugosely punctate, flattened or depressed between the eyes, which are separated by the width of the 
Tostrum; rostrum curved, rugosely punctate, except along the smooth raised median line, which 
becomes cariniform at the base, very much smoother in some specimens of the 9. Prothorax constricted 
and greatly narrowed in front, the sides subparallel at the base; densely punctate and also carinate. 
Elytra subparallel towards the base, narrowing from before the middle, the scutellar region transversely 
depressed ; seriate-punctate, the interstices conspicuously seriato-granulate, the alternate ones raised. 
Beneath coarsely punctate. Anterior femora obsoletely dentate, the anterior tibie serrulate within, and 
the anterior tarsi with joints 1 and 2 strongly dilated on the outer side at the apex, in the 3. 
Length 6-12, breadth 25-53 millim. (¢ @.) 
Hab. Mexico, Orizaba (Sallé); Brivisa Honpvuras (Blancaneauxr); GUATEMALA, 
Panzos, Teleman, San Isidro, Las Mercedes, Pantaleon, Volcan de Atitlan (Champion). 
—Amazoss (Mus. Brit.). 
Found in abundance on both the Atlantic and Pacific slopes of Guatemala on fallen 
timber, the specimens varying greatly in size and to some extent in the development 
