Staphylinidoe of tlie Amazon Valley. 381 



more oljscure; joints 6 — 8 small, 9th transverse, 10th 

 much broader than 9th, strongly transverse, 11th rounded, 

 rather large. Palpi yellow; clypeus with two elongate 

 spines, its front with an emargination on each side. Plead 

 broad and short, with impressions placed much as in M. 

 spinosus, but the depressions formed as it were by con- 

 fluent punctures. Thorax with very coarse punctures 

 covering the greater part of its surface; a series behind 

 the front margin, a second series separated from the front 

 one by a rather elevated space; along the middle with 

 a third, broad, confused, double series, interrupted in the 

 middle, also with a basal series, and with additional 

 punctures (not extending across the middle) in front of 

 the basal series. Elytra bi'oad and short, the sutural stria 

 very deeply impressed at the base, across the middle with 

 a deep oblique impression, and near the inner edge of this 

 with two obsolete pimctures. Hind body with the im- 

 pressions at the base of the segments large and distinct. 

 Legs yellow; coxas darker. 



Villa Nova; a single female, foimd under chips. 



OSORIUS. 



About eighteen species of this genus have been described, 

 eight from warm America, one from North America, and 

 the others from the warm parts of the Old World. I here 

 describe seven Amazonian species, and though this seems 

 a considerable addition to the South American species, it 

 is, in comiiarison with the undescribed species, but small ; 

 for I find the specimens of the genus from South America 

 extant in my own collection must be referred to about 

 forty species. The genus is one of excessive difficulty to 

 the student, from the extreme resemblance of the species 

 to one another ; and it is not until careful examinations 

 and comparisons are made, that the characters distin- 

 guishing the species from one another are seen and appre- 

 ciated. The structure of the species indicate very sedentary 

 habits; the cohesion or attachment of the different parts 

 of the body together is but slight, so that these insects 

 drop to pieces in our collections with only too great ease. 

 It has been observed that some of the species live in 

 burrows in decaying wood, but it is not indicated whether 

 they follow the borings of other insects, or make the 

 burrows for themselves. The almost complete alisence 

 of external characters to distinguish the sexes is worthy of 



