STAPHYLINID.1<:. 59 



characteristics of most of the Florissant Staphylinidaj, it has seemed best 

 to refer them to Leptacinus, with which group they appesar best to agree. 



Leptacinus rigatus sp. nov. 

 PI. VII. fig. 11. 



Head elongate-oval, considerably longer than broad, the sides only 

 slightly convex, the hind angles well rounded, the eyes anterior, small, and 

 scarcely prominent, the surface smooth but very faintly and very sparselv 

 pilose, with three tolerably distinct longitudinal carinae, one median and 

 two postantennal, disappearing before the hind margin; similar but very 

 brief postantennal carinae, are seen in a species of Leptacinus marked 

 doubtfully in Mr. Austin's collection as L.hatyclirus Gyll., with which, better 

 than any other I have seen, this species agrees generally. Antennse reaching 

 to the middle of the thorax, moderately stout, scarcely increasing in size 

 apically, the basal joint fully three times as long as broad, rather stout, the 

 second less than half as long, and only half as long again as broad, the 

 rest scarcely broader than long, with rounded sides. Thorax slightly longer 

 than the head, oval, with well-rounded sides and ends, scarcely broader in 

 front than behind, the surface sparsely punctate, the puncta giving rise 

 each to a rather short hair. Elytra scarcely longer and much broader than 

 the thorax, apically truncate, with the same punctuation and clothing as the 

 thorax. Abdomen about a third as long again as the rest of the body and 

 slender, being at base no broader than the thorax, with nearly parallel 

 sides, but enlarging very slightly to the fifth segment, afterwards narrowing 

 slightly, the tip rounded; the surface is more sparsely punctate than the 

 thorax and elytra, with similar but seemingly shorter hairs, apparently with- 

 out setae or fringes to the joints. 



Length of body, 4.5 mm.; of antennae, 0.8 mm.; breadth of elytra, 

 0.9 mm. 



Florissant, Colorado; one specimen. No. 1794. 



Leptacinus fossus sp. nov. 



PL VII, rig. l± 



Head subquadrate, less than half as long again as broad, the sides par- 

 allel, with rounded posterior angles, rapidly narrowing at extreme base to 



