StaphylinidcB of the Amazon Valley. 211 



A very robust species for the genus. Antennn3 blfiek, 

 rusty towards the apex, slender, nearly as long as head 

 and thorax; 1st joint as long as the five following, 3rd 

 joint longer than 2nd, 4 — 1 1 each a little shorter than its 

 predecessor, each longer than broad. Head broader than 

 the thorax, nearly as broad as the elytra, suborbiculate, 

 being about as broad as long, and narrowed and rounded 

 behind the eyes, the front part but little produced, elevation 

 at base of the antennae very marked ; it is black and quite 

 dull, obsoletely and sparingly punctured; close to the 

 inner margin of the eye is a peculiar ocellatcd puncture, 

 and there is another similar one at the side, some distance 

 behind the eye. Thorax not much more than half as 

 broad as the elytra, subcylindric, about as long as the 

 head, one and a half times as long as broad, dull black, 

 like the head, and obsoletely and sparingly punctured, a 

 little in front of the base, Avith a longitudinal smooth 

 elevation, and on each side of this slightly dej)ressed. 

 Elytra scarcely so long as the thorax, their common width 

 rather greater than their length, densely and rather coarsely 

 punctured; the punctuation rugose. Hind body broad, 

 slightly contracted at the base, black, with the extreme 

 apex rusty, moderately closely and finely punctured ; the 

 side margins much elevated. Legs black, tibire and tarsi 

 a little paler ; lower part of front tibiaa clothed with a 

 fulvous pubescence, the front femora in the middle with 

 a tubercle beneath. 



In the male the 7th segment beneath is furnished in the 

 middle Avith a longitudinal impression, pointed at the front 

 part and there serrate at the margin ; the impressed portion 

 is yellowish, and has at its extremity a rather deep notch, 

 the sides of which are a little sinuate. 



In the female the hind margin of the 7tli segment 

 beneath is slightly emarginate at the extremity. 



Ega; three specimens, 1^,2$. 



Cryptohium maxillosum, Guerin, is closely allied to the 

 C. gigas, and is even a little larger ; it has the upper 

 surface a little more shining, and the 4th and 5th seg- 

 ments of the hind body have, on the upper surface, a 

 longitudinal plica at the base in the middle, of which 

 there is no trace in C. gigas. 



2. Cryptohium plagipenne, n. sp. Latum, nigrum, 

 elytris plaga laterali, ano, femoribusque ex parte rufescen- 



p2 



