OSORIUS. 679 
lateral margins of the thorax are rather strongly elevated behind; the hind angles 
nearly rectang ular, very slightly obtuse. The two apical ventral segments bear a few 
coarse punctures. . 
The series of about fifteen examples shows but little variation. 
4. Osorius dubius. 
Cylindricus, niger, nitidus; antennis pedibusque rufo-piceis; sublevigatus, capite parce subobsolete punctato ; 
clypeo in medio tantum obsolete bisinuato. 
Long. 10 millim. 
Hab. Panama, Volcan de Chiriqui 2500 to 4000 feet (Champion). 
The mandibles are rather long, the left one with a very small tooth-like tubercle on 
the middle. The eyes are scarcely convex. The thorax has the lateral margin strongly 
elevated behind; there is a short obsolete channel on the disc, and the punctuation is 
scarcely visible. The elytra are almost destitute of punctuation, and are only feebly 
coriaceous. The hind body above is quite impunctate, and beneath the terminal and 
penultimate segments rather sparingly punctate. Two examples. 
This and the following species bring the two groups into which I have divided the 
genus very close together. 
5. Osorius levigatus. 
Cylindricus, niger, nitidus ; antennis pedibusque piceis; sublevigatus, capite parce punctato; clypeo late emar- 
ginato. . 
Long. 10 millim. 
Hab. Guatemata, Sinanja and Sabo in Vera Paz (Champion). 
Extremely similar to 0. dubius, but the clypeus cannot be said to be bisinuate in 
front; the punctuation of the head is not quite so effaced, and there is no channel on 
the disc of the thorax. The elytra are smooth and shining, and there is a moderately 
close punctuation on the last two ventral segments; the terminal segments are more or 
less dilute in colour so as to be piceous or rufescent. The mandibles are a little longer 
than in O. dudius, and the left one is bisinuate rather than toothed on the inner 
margin. Three examples. 
6. Osorius boops. 
Cylindricus, niger, vel piceus, sat nitidus ; antennis pedibusque rufis; capite fere lwvigato, subopaco; oculis 
fortius convexis. 
Long. 8 millim. 
Hab. Panama, Volcan de Chiriqui 2000 to 4000 feet (Champzon). 
This is another species with extremely little sculpture, and readily distinguished 
by the more convex eyes. The front margin of the clypeus is broad and rather 
peculiarly formed—the angles being not at all prominent, and the front margin straight 
or feebly emarginate near each angle, and then slightly emarginate in the middle. 
The head has a silky opacity, and some extremely fine and obsolete punctures. The 
thorax is rather broad, but little narrowed posteriorly, the lateral margins behind rather 
