148 HEMIPTERA-HOMOPTERA. 
bt. Disc of the prothorax even; posterior process strongly 
bisinuate, with the apex deflexed . . . . . «. « . Ophicentrus, gen. nov. 
b+. Posterior process of the pronotum starting from just above 
the head and divided at the base into three long and 
slender spines, of which the central one reaches the apex 
of the tegmina, and the lateral pair, if viewed from above, 
resemble very slender lateral supra-humeral horns . . . Stylocentrus, Stal. 
6. Prothorax produced into a porrect or raised process in front ; 
form more or less compresso-elevate . . . . . . . «. Lycoderes, Germ. 
II. Pronotum without posterior process. 
1. Pronotum with lateral horns, which are variable in form, sometimes 
strong, acute, and curved, and sometimes reduced to blunt pro- 
minences. . . . . . . ee ee ew ew we ee) Tolania, Stal. 
2. Pronotum without lateral horns. 
A. Scutellum raised into a strong prominence behind . . . . . Gerridius, gen. nov. 
B. Scutellum not raised. 
a. Ocelli situated close to the margin of the eyes. 
a*, Form elongate-oblong ; vertex of the head raised and 
strongly bilobed; tegmina opaque, with the veins indi- 
stmct. ©... 1 wee ew ee.) «Endoiastus, gen. nov. 
6*. Form obovate; vertex of the head raised, with the raised 
part sinuate; tegmina hyaline, with the veins thick and 
strongly raised. . 2. . 1. 1 1 ww we) t) «Tropidaspis, Stal. 
6. Ocelli situate at a distance from the eyes. 
a*, Tegmina not reticulate, with the veins scarcely visible, 
except at the apex; form obovate; sizesmall . . . . Gargaropsis, gen. nov. 
6*, Tegmina more or less strongly reticulate, especially towards 
the apex, with. the veins thick and strongly raised; form 
oblong; size comparatively large . . . . . . . . Afthalion, Latr. 
PLATYCENTRUS. 
Platycentrus, Stal, Kongl. Sv. Vet.-Ak. Handl. Band viii. 1, p. 48 (1869) ; Ofv. Kongl. Vet.-Ak. 
Forh. xxvi. p. 291 (1869). 
1, Platycentrus acuticornis. (Tab. IX. figg. 10, 10 a-c.) 
Platycentrus acuticornis, Stal, Ofv. Kongl. Vet.-Ak. Forh. xxvi. p. 2917. 
Hab. Mexico (Sallé', Mus. Holm.1), Jalisco (Schumann). 
The very long, sharp, and strongly divergent horns will easily distinguish this species. 
The specimen from Jalisco, a female, is somewhat different from a typical example 
kindly lent me by Dr. Aurivillius ; it is shorter and darker, with the base of the tegmina 
more plainly infuscate, and the pronotal horns straighter and less elevated. Stal, how- 
ever, in his description of the species, says ‘“‘ cornubus subrectis vel leviter curvatis,” 
