Tune 1500.] Casey : On North American Coleoptera. 53 



Alutacetts is the largest species, being fully 1.6 mm. in length, and 

 coniciventris the smallest. The latter greatly resembles a species from 

 South Africa, taken some years ago by the writer. Piceus is very 

 abundant in the coast regions from Monterey northward, and the fe- 

 male described by me as politus does not seem to differ ; it is the only 

 species before me which is represented by both sexes. Individual ex- 

 amples vary but little among themselves in point of size. 



STAPHYLINID/E. 



The genus Homa'usa of Kraatz, represents an isolated group of the 

 subtribe Aliocharina, containing a number of genera for the most part 

 monotypic as far as known. Those before me may be characterized 

 as follows : — 



Antennae n -jointed 2 



Antenna 10-jointed 4 



2 — Prothorax broadly and evenly rounded at the sides, the apical angles rounded 3 



Prothorax broadly angulate at the sides at the middle, the angle rounded, the apical 

 angles obtuse but not rounded, the base arcuate, not sensibly sinuate toward the 

 angles, which are obtuse but not rounded ; two basal tergites broadly, equally 

 nd deeply impressed in about basal half; fine elevated anterior bounding line of 

 the metasternum strongly and narrowly arcuate anteriorly at the middle, the 

 mesosternal process long and finely acuminate, extending to almost opposite the 

 apices of the coxec ; infraorbital elevated line of the head feeble and obtuse ; an- 

 tenna very strongly incrassate ; basal joint of the hind tarsi distinctly shorter than 



the next two combined; [type crassicornis Csy.] Myrmobiota Csy. 



3 — Base of the prothorax transverse and broadly bisinuate, the basal angles nearly 

 right and not at all rounded ; two basal tergites narrowly, deeply and rather 

 abruptly impressed along the basal margin ; antennae moderately incrassate ; an- 

 terior marginal line of the metasternum transverse and only just visibly and very 

 broadly arcuate anteriorly at the middle, the mesosternal process as in Myrmo- 

 biota ; head with the infraorbital ridge very fine, and, between it and the eye, 

 having two additional broad feeble and parallel ridges ; basal joint of the hind 

 tarsi fully as long as the next two combined ; [type acuminata Mark.]. 



Homceusa Krtz. 

 Base of the prothorax arcuate, becoming feebly sinuate near each angle, the latter 

 slightly obtuse and distinctly, though narrowly, rounded ; basal tergites not im- 

 pressed at base ; antennae feebly incrassate, the last joint longer than the two pre- 

 ceding combined and somewhat compressed apically ; mesosternal process angu- 

 late, much shorter than in the two preceding, the metasternal line obscured in 

 the type ; infraorbital ridge fine but distinct, the additional ridges of Homceusa 

 wanting ; basal joint of the hind tarsi distinctly shorter than the next two com- 

 bined ; pubescence longer and more conspicuous ; [type . rinitula Csy. infra.]. 



Soliusa, gen. nov. 



