PHILONTHUS. 417 
56. Philonthus xanthomelas. 
? Belonuchus xanthomelas, Solsky, Hor. Soc. Ross, v. p. 189°. 
Mas. Capite majore, mandibulis ad basin extus oblique dilatatis; femoribus anterioribus ultra medium longius 
spinosis. 
Hab. Norta America, Arizona (Morrison)—Mexico!, Jalapa (Hége), Puebla, 
Capulalpam (Sal/é). 
The resemblance of this insect to Belonuchus formosus is very great, but the male 
characters are quite different, and the colour is of a darker or more dusky red. The 
colour of the breast apparently varies somewhat, for though the mesosternum is black 
in all the examples before me, yet the metasternum in one or two is more or less dusky 
red. The legs vary in colour in a similar manner. The peculiar dilatation of the 
mandibles is not very conspicuous, except when they are extended, and in the smaller 
males is so much reduced that it may in extreme cases almost elude observation. 
Although this insect cannot be placed in Belonuchus at present, owing to the hind 
femora being without spines in either sex, yet I expect it will prove to be the species 
Solsky intended under the name above cited; but as there are certain discrepancies 
between his description and one or two of the details of colour, in addition to the fact 
that the hind femora are unarmed, this identification cannot be considered as un- 
doubted. 
57. Philonthus trochanterinus. (Tab. XI. fig. 6.) 
Rufus ; capite cum antennis, thorace, scutello abdominisque apice nigris; elytris abdomineque parcius punctatis. 
Mas. Trochanteribus posterioribus longe prolongatis, curvatim hamatis, femoribus basi excavata ; stylis analibus 
extrorsum dilatatis. 
Fem. Trochanteribus vix prolongatis, apice libero. 
Long. 10-12 millim. 
Hab. Guatemaa, Capetillo (Champion). 
This species has quite the colour and appearance of an enormous Seloruchus 
formosus, but the very peculiar sexual characters of the male readily distinguish it 
from that species, as well as from B. validus, which it still more resembles on account 
of the similar size. The head is broadly and conspicuously impressed on the middle in 
front; the punctuation of the hind body is much reduced, being both fine and scanty. 
The breast and all the coxe are entirely clear red. ‘The two terminal segments and 
the anal styles are black, as in the two Belonuchi mentioned. ‘There are a very few 
short spines on the front femora of the female, and a rather greater number of slightly 
longer ones on those of the male; the hind femora are quite without spines in each 
sex. In the male there is a rather large emargination on the last ventral plate. An 
example of this sex is figured. 
BIOL. CENTR.-AMER., Coleopt., Vol. I. Pt. 2, March 1880. 3 HH 
