STAPHYLINIDAE. 69 



with a medial bifid tooth; the last joint of the labial palpi is 

 lunate ; the middle coxce are very widely separated, and the tarsi 

 are 5-jointed. The abdomen is strongly margined. 



Thus far the species have been found only in the Atlantic region. 



Group II. — Osorii. 



The group is represented by a single species, Osorius latipes, 

 found under bark on the Atlantic slope, as far as the Rocky 

 •Mountains. 



The body is cylindrical, the middle coxae are contiguous, the 

 tarsi are 5-jointed, and the abdomen is not at all margined. The 

 ligula is corneous. The mandibles are stout, but not toothed. 



The genus Osorius is distinguished from the foreign Holotro- 

 chus by the anterior tibia? being armed with spines. 



Group III.— Oxyteli. 



The body is either cylindrical or depressed, and the abdomen is 

 strongly margined ; the middle coxaa are contiguous, or nearly so ; 

 the tarsi are 3-jointed in all of our genera, except Syntomium. 

 The ligula is membranous, and the mandibles are toothed. The 

 species are found partly in wet places, partly (Platystethus and 

 certain Oxytelus) in dung and other decomposing material. 



Tarsi 3-jointed ; 



Front tibiae with two rows of spines, (body cylindrical). Bledius. 



Front and middle tibiae with one row of spines, (body depressed). 



Platystethus. 

 Front tibiae with one row of spines, (body depressed) ; 

 Middle coxae separated. Oxytelus. 



Middle coxae contiguous. Haploderus. 



All the tibiae without rows of spines ; 



Hind tarsi longer than half the tibiae, (body glabrous). Apocellus. 

 Hind tarsi shorter than half the tibia?, (body pubescent) ; 

 Scutellum not visible. Trogophlceus. 



Scutellum distinct ; 

 Maxillary palpi with the last joint conical acute, ocelli none. 



Ancyrophorus. 

 Maxillary palpi with the last joint elongate, ocelli distinct. (!) 



Distemmus. 

 Tarsi 5-jointed ; antennae with the last three joints wider. Syktomium. 



To Ancyrophorus I refer Trogophlceus planus Lee. ; the last 

 joint of the maxillary palpi is as long, or nearly so, as the third, 

 and is conical and acute. Distemmus is founded upon T. Argus 



