BELONUCHUS. 429 
guished from Philonthus only by the anterior and posterior femora being spinose 
beneath. It has, however, hitherto escaped the attention of writers that this character 
in certain of the species is confined to the male sex, and even in this sex varies greatly 
in its development according to the species, and in the case of some species is subject 
even to individual variation. This remark applies to the armature of the posterior 
femora only, for that of the front legs is so very variable both in Philonthus and Belonuchus 
that no reliance can at present be placed on it as a generic character. It would thus 
almost appear that the proper course would be to merge Belonuchus into Philonthus ; but 
it is very undesirable to adopt such a course in a faunistic work, and it is also well to 
avoid, if possible, increasing the bulk of a genus already so unwieldy as is Philonthus. 
Moreover, there are characters which will cause Belonuchus to be recognized as valid 
when Philonthus is divided, as it will ultimately be. In Philonthus it is very rarely 
the case that the posterior femora are spinose, and in the few species where we find 
this there is but a single series of spines, whereas in Belonuchus there are always two 
series, one on each of the ridges existing on the posterior face of the femur. The 
species of Belonuchus, too, have, without exception, the lateral margin of the thorax so 
much inflexed that it is remote from the longer of the lateral tactile sete. 
Belonuchus comprises about forty species besides the new ones here defined, and is 
characteristic of the Tropical-American fauna, two or three species only extending their 
range to the United States of North America ; a few species have also been recorded from 
the Austro-Malay region, but these are doubtfully congeneric with the New World 
forms. 
1. Belonuchus cognatus. (Tab. XI. fig. 9.) 
Elongatus, depressus, nitidulus, nigerrimus ; abdominis segmentis duobus ultimis rufis. 
Long. 11-13 millim. 
Hab. Britisn Honpuras, Belize (Blancaneauz) ; GuateMaa, El Reposo, Las Mercedes, 
San Isidro, Mirandilla (Champion) ; Nicaragua, Chontales (Janson); Panama, Bugaba 
(Champion). 
This insect is exactly similar to B. hemorrhoidalis, Kr., except that the two terminal 
segments, as well as the armature, are entirely reddish yellow; as this difference is 
without variation in a large series of examples, it is probably a mark of specific 
difference. 
2. Belonuchus dichrous. 
Belonuchus dichrous, Evichson, Gen. et Spec. p. 420°. 
Hab. Mexico, Orizaba1, Cordova, Tuxtla, Playa Vicente (Sallé), Oaxaca, Mirador 
(Hoge), Jalapa (Flohr, Hoge); Guatemala, near the city, Las Mercedes (Champion). 
This insect, Mr. Champion informs me, is found under bark still saturated with sap. 
