DIASTETHUS. 227 
¢. Prosternum unarmed; anterior tibie with the uncus at the apex developed into a long, broad, flattened, 
truncated process, the intermediate pair also with a broad spoon-shaped process at the tip; first ventral 
segment flattened in the middle. 
Length 42-64, breadth 31-4 millim. (¢ 2.) 
Hab. Mexico, Panistlahuaca in Oaxaca (Sallé); Guatemata, Panzos (Champion) ; 
Nicaragua (Sad/é), Chontales (Belt); Costa Rica, Guanacaste (Pittier). 
Eight specimens. The dense golden vestiture of the pro- and metasternum, the two 
small clusters of scales on the scutellum, the very shallow prosternal sulcus, and the 
peculiar armature of the anterior and intermediate tibie of the male distinguish 
D. pilipectus. 
6. Diastethus mexicanus. (Tab. XIII. figg. 6, 6a, 3.) 
Centrinus mexicanus, Boh. in Schénh. Gen. Cure. viii. 1, p. 244 (nec Pascoe) *. 
Centrinus subarmatus, Boh. loc. cit. p. 247°. 
Broad, subrhomboidal, shining, black, glabrous above, the punctures of the under surface each bearing a hair- 
like scale. Rostrum stout, rather short, the antenne inserted at about the middle. Prothorax smooth, 
sometimes with minute scattered punctures at the sides, depressed at the base on each side of the median 
lobe. Scutellum transverse. LElytra deeply striate, the strie feebly punctate and becoming shallower 
towards the sides, the interstices smooth and flat, the sutural region slightly depressed at the base. 
Prosternal sulcus broad and deep. Anterior femora flattened and unidentate, the others sulcate and 
bidentate, beneath. Tuibice triangularly dilated near the apex externally, the anterior pair sinuate. 
¢. Prosternum armed with two spines, which vary in length and are sometimes wanting; first ventral 
segment slightly depressed down the middle; anterior tibiw feebly hollowed towards the apex within. 
Length 4-61, breadth 27-43 milliim. (¢ 2.) 
Hab. Mexico? (Mus. Brit.), Orizaba, Toxpam, Playa Vicente, Vera Cruz', Santa- 
comapan, Panistlahuaca (Sal/é), Cordova (Hoge), Amula (H. H. Smith), Temax in 
N. Yucatan (Gaumer); British Honpuras, Rio Sarstoon (Llancaneaux); GUATEMALA, 
Panima in Vera Paz, Duefias (Champion), Chimaltenango (Conradt). 
A broad form, with rather deeply punctate-striate elytra, the interstices of which are 
broad, smooth, and flat throughout. The anterior femora are unidentate. I have seen 
the types of the two insects described by Boheman, and am unable to separate them ; 
that of C. subarmatus is also from “ Vera Cruz.” Pascoe’s C. mexicanus, the type of 
his genus Rhianus, is a very different insect. 
7. Diastethus ater. (Tab. XIII. fig. 7.) 
Centrinus ater, Boh. in Schéuh. Gen. Cure. vill. 1, p. 251°. 
Subrhomboidal, shining, black, the antenne sometimes ferruginous ; glabrous above, the punctures of the 
under surface each bearing a minute hair-like scale. Antennal club ovate. Prothorax smooth or with 
a few widely scattered minute punctures. Scutellum strongly transverse. Elytra triangular, at most 
faintly depressed along the suture at the base; deeply striate throughout, the strie feebly punctate, the 
interstices smooth and flat. Prosternal sulcus broad and deep, extending between the anterior coxe. 
Femora each with two small teeth (one on each edge of the shallow groove beneath) and sometimes with 
two or three minute denticles also. 
2GG 2 
