108 HETEROMERA. — 
raised obliquely on each side in front, and concave within, but the angles are not pointed as in Derils) ; legs 
smooth, rather short ; femora stout, incrassate, the anterior pair rarely toothed in the male (IV. caliginosus) ; 
anterior tibise curved, in the male with a short triangular tooth on the inner side near the middle, rarely 
with two teeth (one in the middle, the other nearer to or at the apex) ; the extreme apices of the tibie 
and the basal joints of the tarsi more or less densely clothed with silky yellowish hair beneath ; inter- 
mediate and posterior tibiz in one or two species slightly swollen in the middle in the male; epipleure 
narrowing gradually from the base, terminating somewhat abruptly at the last ventral suture, and 
scarcely attaining the apex. Winged. Form elongate oval, subparallel, convex, slightly depressed above. 
The above description has been drawn up to receive several Central-American species, 
one or two of which are also found south of the Isthmus of Panama. It will include 
the undescribed Jphthimus cornutus, Laferté, of collections; the Nuptis tenuis, Motsch., 
from Nicaragua, is probably congeneric with the species here described, though the author 
makes no mention of the structure of the anterior tibie, epipleure, &c. Most of the 
characters of this, and of @atus, are taken from a carefully prepared but unpublished 
revision of the “ Ténébrionides vrais of Lacordaire,” made long ago by Mr. F. 
Bates. Nuptis might easily be divided, the form of the pro- and mesosternum differing 
in various species; but the structure of the maxille, mandibles, tibie, and epipleure 
being similar in all the species known to me, I prefer to place them in one genus. 
Somewhat similar variations in the form of the epistoma of the male in the different 
species may be seen in Centronopus. This genus is allied to Taphrosoma, Kirsch 
(Orobychus, Pascoe), from which, apart from the more transverse thorax and much smaller 
size, it differs in the shape of the mentum, epipleure, &c. A good many allied and 
mostly undescribed forms, probably generically distinct, are found in Tropical South 
America; one of which, the Tenebrio variolosus, Fabr., is known in collections. 
These insects, like Nyctobates, are found under loose bark. Owing to the hard, 
tough integument of the elytra, and the loosely attached parts of the body, they are 
difficult to pin, and frequently come to pieces under that operation. 
a. Epistoma in the male margined in front, and with a short erect tubercle 
in the middle. 
1. Nuptis tenuis. 
Nuptis tenuis, Motsch. Bull. de Moscou, xlv. pt. 2, pp. 25, 32°. 
Hab. Nicaracva }. 
I am unable to identify this species amongst the large number of Central-American 
specimens of the group before me. Judging from the size given (6% lines), WN. tenuis is 
smaller and narrower than any of the species here recorded. 
2. Nuptis cornutus. 
Iphthimus cornutus, Laferté, in litt. 
Biack, shining. Head with some scattered shallow coarsish punctures, impressed between the eyes ; epistoma 
in the male concave within, well defined posteriorly by a transverse impression, the anterior margin raised 
