Stap]iylinid(B of tlie Amazon Valley. 381 



more obscure; joints 6 — 8 small, 9tli 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. Head 

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

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

 fluent punctures. Thorax Avith very coarse punctures 

 covering the greater part of its surface ; a series behind 

 the front margin, a second series separated fi-om the front 

 one by a rather elevated space; along the middle Avitli 

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

 middle, also with a basal series, and Avith additional 

 punctures (not extending across the middle) in front of 

 the basal series. Elytra broad and short, the sutural stria 

 A'erv deeph^ impressed at the base, across the middle Avith 

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

 Avith two obsolete punctures. Hind body Avith the im- 

 pressions at the base of the segments large and distinct. 

 Legs yelloAv; coxre darker. 



Villa Nova; a single female, found under chips. 



OsoKius. 



About eighteen species of this genus have been described, 

 eight from Avarm America, one from Xorth America, and 

 the others from the Avarm 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 comparison Avith 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 imtil carefid 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 ditterent parts 

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

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

 It has been observed that some of the species live in 

 burrows in decaying Avood, but it is not indicated Avhether 

 they follow the borings of other insects, or make the 

 burrows for themselves. The almost complete absence 

 of external characters to distinguish the sexes is worthy of 



