62 INSECTA. 



linear, with the thorax nearly square, and not narroAved posteriorly, 

 form two suhgenera. 



Stenotracheeus. — Dryops, Payk. 



Where the head is elongated, and narrowed posteriorly almost in 

 the manner of a neck ; the antennae are abruptly terminated by three 

 joints, shorter and somewhat thicker than the rest ; the third is 

 much longer than the following ones *. 



Strongylium, Kirb. — StenoChia, ejusd. — Helops, Fab. 



Where the head is neither elongated nor narrowed posteriorly, and 

 the last joints of the antennae — somewhat more dilated — do not sud- 

 denly differ from the preceding ones ; the thii'd is merely somewhat 

 longer than the following one f . 



Those, in which the body is flattened, and the thorax narrowed 

 posteriorly almost in the form of a truncated heart, compose the last 

 subgenus, that of 



Pytho, Lat,. Fab., 

 Where the antennas hardly enlarge towards the extremity, or are 

 filiform, with the last joint almost conical ; the third is hardly longer 

 than the preceding and following ones. 



Certain species peculiar to Brazil closely approach Pytho ; but 

 the second joint is much shorter than the third, and the angles of 

 the thorax are acute, instead of being rounded or obtuse as in that 

 genus |. 



The second tribe, that of the Cistelides, is very closely allied 

 indeed to the first, but the insertion of the antennae is not covered, 

 the mandibles terminate in an entire or unemarginate point, and the 

 hooks of the tarsi are pectinated inferiorly. Several of these Insects 

 live on flowers. The digestive canal is shorter than in Helops, and 

 the chylific ventricle presents no papillae. 



This tribe forms the genus 



CiSTELA, Fab. 

 In some, all the joints of the tarsi are entire. The last of the max- 

 illary palpi is merely somewhat larger, and obconical or triangular. 



* Dryops eenna, Payk. ; Calopus emeus, Gyll. : (Edetnera <mea, Oliv. The Agna- 

 ihus dccoratus of Germar — Faun. Insect. Europ., fascic. XII, fig, 4 — a specimen of 

 which I found near Brives, appears to me to approximate closely to the Stenotra- 

 cheles. The Pelmatopis Hummelii, Fisch. — Entom. Imp. Russ., II, xxii, 7 — is, I 

 presume, congeneric and closely approaches the first species. 



N.B. Pelmatopus. M. Fischer, who at first thus designated this genus in his 

 plates, has, in the text, adopted the name of Scotodes, previously given to it by 

 M. Eschscholtz. 



f Strongylium chalconafum, Kirb., Lin. Trans., XIT, xxi, 16: — Sfenochia rufipes, 

 lb., xxii, 5. See also the Helops splendidus, aurichalceiis, azureus, interstitialis,flavi- 

 crus, luteicornis, limbatus, of Germar. 



X See Fab., System. Eleuth., II, p. 95 ; Lat. Gener. Crust, et Insect., II, p. 

 195 ; Schcenh., Synon. Insect., I, iii, p. 55 ; Frisch., Entom. Imp. Russ., II, xxii, 1. 



