PSEUDOCENTRINUS.—GERAOPSIS. 327 
interstice, the lines becoming doubled or trebled at or towards the base; the under surface thickly 
clothed with coarse white scales. Head closely punctate, foveate between the eyes; rostrum strongly 
arcuate, stout, about as long as the head and prothorax, closely punctate, a little smoother in the @, the 
antenne inserted at about the middle. Prothorax transverse, constricted in front, arcuately narrowing 
from the base; coarsely, closely punctate, sometimes with a smooth central line. Elytra subtriangular, 
punctato-sulcate, the interstices coarsely and roughly uniseriate-punctate. Prosternal sulcus well- 
defined, but partly hidden by the vestiture. Beneath densely punctate ; ventral segment 5 slightly longer 
than 2. Tibie strongly unguiculate. 
3. Ventral segment 1 depressed down the middle and 5 sinuato-truncate at the apex, leaving the vertical 
pygidium narrowly visible from beneath. . 
@. Ventral segment 5 transversely convex, the pygidium covered by the elytra. 
Length 32-4, breadth 13-2 millim. (¢ @.) 
Hab. Mexico, Toxpam (Sallé, in Mus. Dresden: 9 ), Chilpancingo and Soledad in 
Guerrero (H. H. Smith: 3); GuateMata, near the city (Salvin: ¢ ), Duefias and San 
Geronimo (Champion: ¢ ). 
Seven specimens, all males but one, varying in the sculpture of the prothorax and 
in the colour and amount of the elytral vestiture, the single example from Chilpancingo 
having a transverse brown space on the disc of each elytron below the base. ‘The 
shorter rostrum, the more approximate anterior cox, the sulcate prosternum, and the 
fully-exposed pygidium of the male distinguish the present species from Gereus 
gaumeri, for which it might very easily be mistaken. | 
GERZOPSIS, gen. nov. 
Rostrum stout, arcuate; mandibles decussate, obliquely truncate externally ; antenne inserted beyond the 
middle of the rostrum, the club ovate ; prothorax tubulate in front; scutellum free; elytra triangular, 
much wider than the prothorax; pygidium not visible; prosternum unarmed, narrowly sulcate from 
the apex to between the anterior coxw, the posterior portion very broad, extending backward between 
the intermediate coxe, and almost covering the short mesosternum; anterior coxe separated by con- 
siderably less than their own width, the two other pairs widely separated; legs short ; femora sublinear, 
sulcate along their entire length beneath ; anterior tibie hollowed at the apex externally for the reception 
of the first tarsal joint; tarsal claws free ; body rhomboidal, broad, squamose. 
Type, G. duplocinctus. 
The insect from which the above characters are taken cannot be satisfactorily 
referred to any of the other genera of Centrinids here enumerated, even if no value is 
placed upon the mandibular structure. One species with sulcate femora (G. arcuati- 
rostris) is included under Gerwus, but it has the rostrum, &c., differently formed. 
The prosternal structure approaches that of Platyonyx, which, however, has a longer 
mesosternum. 
1. Gerxopsis duplocinctus, sp.n. (Tab. XVII. figg. 9, 9a, ¢.) 
Nigro-piceous or piceous, the antenne and tarsi obscure ferruginous; the prothorax with a large space on 
each side at the base, and the elytra with the base and a broader transverse space towards the 
apex, the latter extending down the suture to the tip, clothed with small, narrow, ochraceous scales, 
the rest of the elytra (a few scattered whitish scales excepted) with black scales, the disc of the 
prothorax, the base of the rostrum, the under surface, and legs with scattered ochraceous or whitish 
scales. Head opaque, finely punctate, transversely grooved between the eyes; rostrum not longer than 
