744 STAPHYLINIDA. 
In this species the thorax becomes broader from the apex to the base; the sides are 
sinuate so as to form three obscure angles between the front and the hind angle; the 
latter is remarkably acute, and behind it is a very abruptly defined excision. The 
sculpture is coarse. 
Only one example was procured ; it is apparently a female and is not in very good 
condition; the terminal joint of the antenne is elongate and appears to be a little paler 
than the others. 
Subfam. OMALITNA. 
OMALIUM. 
Omalium, Gravenhorst, Col. Micr. p. 111 (1802) ; Erichson, Gen. et Spec. Staph. p. 871 (1840). 
Homalium, Gemminger & Harold, Cat. Col. ii. p. 665 ; Fauvel, Notices ent. vii. p. 41. 
This genus, taken in the larger sense of the Munich Catalogue, includes about 120 
species, most of them European; Fauvel (¢. c.), however, records 23 North-American 
species. Many genera have been proposed for the European species, but these it would 
not be possible to accept at present, as they are based on very slight characters and on 
an examination of only a portion of even the European forms. 
As yet our region has produced only eight or nine extremely obscure species (which 
may perhaps ultimately form a genus allied to Anthobium as well as to Omalium), and 
Tropical South America has so far only a single equally obscure representative. Thus 
as we have no other genera of the subfamily to record, and as North America is very 
rich in this subfamily, it is evident that we have here a striking contrast between our 
region and that of North America. It may be worth while to mention that of our 
eight or nine species, four have been found only in what may be looked on as the 
alpine parts of our region. 
1. Omalium sordidum. 
Depressum, nigricans, subopacum, parce subobsolete punctatum ; antennarum basi pedibusque sordide testa- 
ceis ; elytris fusco-rufis, marginibus plus minusve argute nigricantibus, 
Long. 23-3 millim. 
Hab. Mexico, Cordova (Sallé) ; GuatemaLa, Cerro Zunil, Capetillo, Zapote, Carrizal, 
near the city, San Geronimo (Champion). 
Thorax very strongly transverse, without fovez on the disc, sparingly and indistinctly — 
punctured, twice as broad as long, rounded at the sides; hind angles obtuse. Elytra 
nearly twice as long as the thorax, rather sparingly and finely punctured ; of an obscure 
reddish colour, usually more dilute on the humeral region, and the hind margins and 
side margins blackish. The male has the posterior part of the metasternum impressed 
with a deep groove in the middle, the margins of the groove being plicate; the 
terminal ventral segment broadly emarginate. 
