108 HEMIPTERA-HETEROPTERA. 
Two Nicaraguan specimens are figured, which are slight colour-varieties of this 
species. Both specimens are males, but show a considerable contrast in the thickness 
of the posterior femora. 
THASUS. 
Thasus, Stal, Ann. Soc. Ent. Fr. sér. 4, v. p. 174 (1865) ; Ofv. Vet.-Ak. Forh. 1867, p. 538. 
This genus is closely allied to the last, from which it is separated by the dilatation of 
the posterior tibize on both sides. 
Four species are recorded, all of which are Neotropical, one only, according to present 
knowledge, being also known as a Southern Nearctic form. 
1. Thasus gigas. (Tab. X. figg. 189,192.) 
Pachylis gigas, Burm. Handb. ii. 1, p. 338.3"; Blanch. Hist. des Ins. p. 121. 1°; Dall. List Hem. 
ii. p. 883. 2°; Uhler, Bull. U.S. Geol. & Geog. Surv. ii. p. 295*; Wheeler’s Rep. Geog. Explor. 
v. Zool. p. 881°; Town. Glov. Ill. Ins. Ord. Hem. p. 56, t. vii. f. 23 g, pupa, t. vill. f. 36°. 
Thasus gigas, Stal, En. Hem. i. p. 182. 17. 
Pachylis, sp., Dugés, La Nat. iii. p. 52. ff. 1-7°. 
Hab. Norra America, Arizonat®®, New Mexico4.—-Mxxico! 2347, 
The males of this species which I have examined vary in size from that of the one 
figured (Tab. X. fig. 19) to smaller specimens of only 37 millims., which last dimension is 
also that of the few females which I have seen. The red bands to the posterior femora 
of the males are also somewhat inconstant, as in one small specimen which I possess they 
are only faintly indicated. The figure given by Townend Glover (in his somewhat inac- 
cessible publication) is either that of a slight variety, or has not been sufficiently coloured 
by the artist. 
As described by Prof. Uhler, “ the nymph, probably in its fourth dress, is almost equally 
showy, but is differently painted. Its ground-colour is dark steel-blue, velvety; the 
scutellum cadmium-orange; the venter with large broad bands along the middle; the 
tergum with transverse white streaks, and a row of short white lines on the middle, with 
a series of carmine spots each side of the middle line, and with the femora and tibie 
banded with cadmium, but with entirely blue-black antenne.” Dr. Dugés® states that 
this species is found on Acacia albicans, and emits a red fluid by means of organs 
which he describes and figures. 
2. Thasus acutangulus. (Tab. X. figg.16 3 & 172.) 
Pachylis acutangula, Stal, Ofv. Vet.-Ak. Férh. 1858, p. 439°. 
Pachylis acutangulus, Stal, Stett. ent. Zeit. xxiii. p. 275. 124°. 
Thasus acutangulus, Stal, En. Hem. i. p. 1382. 2°. 
Hab. Mexico!??; Brirish Honpuras, river Sarstoon (Blancaneausr) ; GUATEMALA, 
Senahu, Cerro Zunil (Champion). 
