678 STAPHYLINIDA. 
§ 1. Lateral margins of the thorax more strongly elevated near the base. 
1. Osorius canaliculatus. (Tab. XVIII. fig. 3.) 
Osorius canaliculatus, Solsky, Bull. Mose. xlii. pt. 2, p. 265 (1869) *. 
Hab. Mexico (Boucard1), Orizaba (coll. Chevrolat), Cordova (Salié), Jalapa (Hoge) ; 
Guatemaa, Chiacam, Tactic, Senahu, Sinanja (Champion); Panama, Bugaba (Cham- 
pion). 
Of this insect we have obtained single examples from most of the above sources, 
and though I can find no good characters to distinguish more than one species among 
them, it is quite possible there may prove to be such. Our figure represents an 
example from Sinanja. 
2. Osorius puncticeps. 
Angustulus, cylindricus, niger, nitidus ; antennis pedibusque piceis; capite crebrius minus subtiliter punctato ; 
prothorace basin versus fortiter angustato, sat crebre subtiliter punctato, medio canaliculato; elytris parce 
punctatis. 
Long. 12 millim. 
Hab. Mexico (Truqui, Flohr), Orizaba (coll. Chevrolat), Jalapa, Cerro de Plumas 
(Hoge), Tuxtla (Sallé), Cordova (Sallé, Hoge). 
Mandibles rather long and slender, the teeth quite minute. Thorax just about as 
long as it is broad at the base, strongly narrowed behind, the lateral margins much 
raised on the posterior part; hind angles definite, rectangular. Elytra slightly longer 
than the thorax, with distant, but distinct, punctures. Hind body with a very few 
punctures on the upper surface; on the under surface the penultimate and terminal 
segments are rather sparingly punctate. 
Readily distinguished from 0. canaliculatus by the conspicuous punctuation of the 
head, and by the terminal ventral plate not possessing coarse deep longitudinal ruge. 
Some examples have a rather dense punctuation on the terminal ventral segments, 
due, I consider at present, to variation, or possibly it may be a sexual character. 
Most of the examples, except for the above characters, agree satisfactorily, but 
there are one or two showing other slight differences that may possibly be indicative 
of another species. 
8. Osorius vicinus. 
Cylindricus, niger, nitidus ; antennis pedibusque piceis; capite fortiter punctato ; prothorace transverso, crebre 
punctato ; elytris parce punctatis; mandibulis argute dentatis. 
Long. 11 millim. 
Hab. Panama, Bugaba, Volcan de Chiriqui 2000 to 4000 feet, Caldera (Champion). 
Extremely similar to O. puncticeps, but readily distinguished by the well-defined 
teeth of the mandibles; the thorax also is broader and less narrowed behind, and hasa 
short channel on the disc. The clypeus is feebly bisinuate, its angles obtuse. The 
