SUBFAMILY II. — MEZIRIN^. 317 



KEY TO EASTERN" GENERA OF MEZIRIN.^. 



a. Antennas very short, the two basal joints united not reaching apex 

 of tylus; scutellum very long and narrow, extending beyond the 

 middle of abdomen; elytra membranaceous, the corium linear; 

 length, less than 4 mm. I. Calisius, p. 317. 



aa. Antennae longer, the second joint always extending beyond apex of 

 tylus; scutellum of medium size, triangular or with apex rounded; 

 elytra in part coriaceous, the corium usually distinct from mem- 

 brane. 

 b. Scutellum triangular, never wider than long; fourth joint of an- 

 tenna? but little if any longer than third, often much shorter. 

 c. Venter more or less convex, its third, fourth and fifth segments 

 without a carina or keel between the spiracles and side margin. 

 d. Pronotum with side margins near middle bi-marginate or bi- 

 sinuate, its surface not granulate or rugose, but with callosities 

 formed of a pale crust; color pale brown or grayish; rostral 

 groove lanceolate. II. Proxius, p. 318. 



del. Pronotum with side margins straight or unisinuate near middle; 

 surface granulate or rugose; color black or dark reddish 

 brown, rarely paler; rostral groove linear. 

 e. Membrane without distinct veins; third joint of antenna? (in our 

 species) longer than second. III. Pictinus, p. 320. 



ee. Membrane with distinct veins. 



/. Length, less than 4 mm. ; base of thorax trisinuate in front of 



scutellum; spiracles placed near the side margins of ven- 



trals. IV. Nannium, p. 320. 



ff. Length, 5 or more mm. ; base of thorax truncate in front of 



scutellum; spiracles equally distant from front, side and hind 



margins of ventrals; third joint of antenna? distinctly longer 



than second. V. Mezira, p. 321. 



cc. Venter very flat, its third, fourth and fifth segments with a 



carina or keel between the spiracles and side margins; third 



joint of antenna? but little longer than second. 



VI. Neuroctenus, p. 324. 

 bb. Scutellum as wide or wider at base than long, its apex very broadly 

 rounded; fourth joint of antenna? much longer than third; mem- 

 brane without veins. VII. Aneurus, p. 327. 



I. Calisius Stal, 1860, 67. 



Very small pale brown or fuscous-yellow species having the 

 antennae shorter than head ; margins of rostral sulcus parallel, 

 distant throughout their length ; sides of metanotum and first 

 dorsal visible from above ; pronotum with two to four short 

 ridges on both front and hind lobes ; osteolar opening distinct, 

 punctiform, placed in front of hind coxae. Two of the half- 

 dozen known species occur in Florida. 



KEY TO EASTERN SPECIES OF CALISIUS. 



a. First joint of antenna? slightly surpassing apex of antenniferous 

 spines; color fuscous-ochraceous, sometimes darker. 



248. CONTUBERNALIS. 



