166 HEMIPTERA-HOMOPTERA. 
in having the head and pronotum simple, without horns, and in the formation of the 
external apical areas of the tegmina, which are not deflexed. 
1. Gerridius scutellatus, sp.n. (Tab. X. figg. 11, 11 a, 4.) 
Nigro-piceus, capite pronotoque vix nitidis perdense et subtilissime granulatis, illo margine postico flavo-testaceo, 
hoc basi extrema angustissime testaceo limbata, lined levi centrali vix distincté; scutello nigro, protu- 
berantié picea postice albo-limbaté; tegminibus vitreo-hyalinis, basi extrema, et apice clavi coriique, 
nigris; pedibus fusco-testaceis. 
Pitchy-black, with the head and pronotum not or scarcely shining, very thickly and finely sculptured, hind 
border of the forehead comparatively broadly, and hind margin of the pronotum very narrowly, testaceous, 
central line not very distinct; scutellum black, extremely finely punctured, with the protuberance, if 
_ viewed from the side, in part pitchy and rather broadly bordered behind with white; tegmina very 
shining, hyaline, with the extreme base, the apex of the clavus and of the corium, a spot at the centre 
of the former, and the internal margin before the apex, pitchy-black; legs fusco-testaceous; abdomen 
mostly infuscate. 
Long. 42 millim.; lat. int. hum. 2 millim. 
Hab. Panama, San Lorenzo (Champion). 
One male specimen. 
TOLANIA. 
Tolania, Stal, Ofv. Kongl. Vet.-Ak. Férh. xxiv. p. 248 (1858); Bidr. till Rio Janciro-Traktens, 
Hemipter.-Fauna, p. 36. 
This is one of the transitional genera of the Membracide, in which the pronotum 
has no posterior process; it is, however, in all other respects a true Centrotid, and the 
species were assigned to the genus Centrotus, until Stal characterized the genus. 
1. Tolania opponens. (Tab. X. figg. 12, 12a, 2; 18, 184, var., 9.) 
Centrotus opponens, Walk. List of Homopt. Ins., Suppl. p. 1597. 
Hab. Mexico (Sallé1); Guatemata, Sinanja, Chiacam, and Cubilguitz in Vera 
Paz (Champion); Panama, Bugaba, Volcan de Chiriqui 2000 to 4000 feet, David 
(Champion). 
There is a series of about forty specimens of this species in our collection; they vary 
very much in size and in the development of the pronotal horns, which are occasionally 
wanting or only partially developed. The difference in the form of the horn is not 
a sexual character. We figure a typical specimen from Sinanja and a variety from the 
Volcan de Chiriqui, bdth females. 
2. Tolania obtusa, sp.n. (Tab. X. figg. 14, 14 a.) 
Precedenti simillima sed scutello breviori, apice late rotundato, postice densius et fortius punetato, tegmini- 
busque areis apicalibus plerumque angustioribus distinguenda. 
This species may easily be distinguished from 7’. opponens by the shape of the scutellum, which is much less 
elongate, broadly rounded, and more punctured behind; the areas of the tegmina are somewhat variable 
