122 HEMIPTERA-HOMOPTERA. 
This is a very remarkable genus, differing from Proteinissus in several particulars, 
but especially in the shape of the frontal process, which gives the insect a very bird- 
like appearance, if viewed from the side. 
1. Ornithissus cockerelli, sp.n. (Tab. XII. figg. 14, 144, ¢.) 
Griseo-testaceus, colore dilutiori obscure variegatus ; vertice convexo, nitido; pronoto ad medium carinato 
utrinque impresso; scutello haud nitido; tegminibus ad partem brunneis, albido-testaceo sparsim 
notatis; alis lacteis ; pedibus plerumque testaceis. 
Femina segmento ultimo ventrali late emarginato, processu anali lato ad apicem bifisso, marginibus late 
deflexis. 
Of a greyish-testaceous colour, more or less obscurely variegated ; vertex convex, shining; forehead brown, 
with the carinz well-marked and lighter; pronotum with a small dark impression on each side of the 
central keel; scutellum with four small impressions, two on each side; tegmina in part brownish, with 
irregular whitish-testaceous markings; wings milky-white ; legs in great part testaceous. 
Female with the last ventral segment of the abdomen broadly emarginate, and the anal process broad, with 
the margins much turned down and their apex bifid. 
Long. cum tegm. et processu antico 64 millim.; sine processu antico 5 millim. ; lat. ad hum. 3 millim. 
Hab. N. Mexico, Juarez (Cockerell). 
A single female specimen, found on the northern frontier of Mexico. 
THIONITA. 
Thionia, Stal, Berl. ent. Zeitschr. 1859, p. 321. 
This genus is characterized by having the radial vein forked just after the base, the 
exterior ulnar vein forked before the middle, and the interior ulnar vein not forked, 
and also by the posterior tibiz being armed with two spines. The simple interior 
ulnar vein and the bispinose tibiz appear to be correlated in a large number of species 
belonging to the family Isside. ‘The external area of the wings, which are large and 
notched, has a large antler-shaped vein with several branches. 
1. Thionia variegata. (Tab. XII. figg. 15, 15a; 16, var.) 
Thionia variegata, Stal, Stett. ent. Zeit. xxv. p. 51°. 
Hab. Mexico (coll. Signoret!), Atoyac in Vera Cruz (Schumann); Guatemata, 
Panima in Vera Paz, Cerro Zunil (Champion); Panama, David, Bugaba, and Volcan 
de Chiriqui (Champion). 
The name given by Stal to this insect is rather misleading, as it is apparently 
rarely variegated. The specimens in our collection are for the most part almost 
unicolorous, of a brownish-testaceous colour, as also is the single example in the 
Signoret collection at the Vienna Museum. We figure two specimens from 
Chiriqui, 
