HETEROMERA. 559 
Hab. Mexico, Paso del Norte in Chihuahua (Hége). 
Three specimens, all females. This species differs from H. rastratus and H. spissi- 
corms in having the punctures of the elytral series much coarser, deeper, and more 
regular, the thorax almost immarginate at the sides and with prominent hind angles 
(sculptured as in H. spissicornis), the antenney much longer, the elytra subelliptic in 
shape, the last joint of the maxillary palpi narrower and more ovate. In one specimen 
the venter is more sparsely punctured. 
MENTES. (To follow the genus Helops, p. 320.) 
‘Mentum trapezoidal; last joint of the maxillary palpi oblong, subsecuriform, that of the labial pair very 
broad and stout, truncate at the apex; mandibles bifid at the tip; ligula entire; labrum prominent,. 
separated from the epistoma by a narrow coriaceous space; head convex, declivous, short, with the 
antennary orbits exceedingly narrow, converging, and scarcely projecting beyond the point of insertion of 
the antenn ; the epistoma short, truncate in front, scarcely defined posteriorly ; the eyes large, deeply 
emarginate, oblique if viewed from above; antennew elongate, joints 1 and 2 very short, 3 much shorter 
than 4, 4-11 longer than broad ; prothorax convex, transverse, finely margined at the sides, truncate at 
the base and apex, transversely sulcate behind; scutellum transverse, moderately large, rounded behind ; 
elytra closely fitting to the prothorax at the base, elongate-oval or fusiform ; epipleure entire, moderately 
broad at the base, and gradually narrowing to the apex; anterior coxe strongly exserted, subcontiguous, 
the prosternum acutely raised between them behind and with a raised point at the apex; anterior coxal 
cavities closed behind; middle coxe narrowly separated, with small trochantin; metasternum elongate ; 
intercoxal process of the abdomen rather broad, subtriangular ; third and fourth ventral segments with 
coriaceous hind margin; legs elongate, very slender; tarsi clothed with long, fine hairs beneath, the 
penultimate joint of all three pairs simple, narrow, the hind pair equalling the tibie in length, their first 
joint exceedingly elongate, as long as the other three joints united; tibial spurs distinct; body elongate, 
narrow, fusiform, winged. 
This genus is proposed for three species from Central America, of which we have 
only received four specimens in all, and these females. 
Mentes is perhaps best placed at the end of the Group Helopides, of which it may 
be considered a degraded form. 
1. Mentes ruficollis. (Tab. XXIII. figg. 14,9 ; 14a, maxilla and maxillary 
palpus.) 
Elongate, fusiform, moderately convex, very opaque, black, the prothorax rufous. Head small, densely and 
rather coarsely punctured, shallowly, transversely grooved in front; eyes moderately large, but not pro- 
minent, rather finely granulated; antennz black, elongate, joint 2 very short, 3 nearly twice as long as 2, 
very much shorter and narrower than 4, 4-11 moderately stout, longer than broad, subequal; prothorax 
transverse, much wider at the base than at the apex, the sides converging almost from the base, rounded 
anteriorly, the anterior angles declivous and very obtuse, the hind angles acute, the disc with a transverse 
groove behind limited on either side by a foveate depression, the entire surface thickly, finely punctate ; 
elytra about four and a half times as long as the prothorax, widest at the middle, and narrowing thence 
to the apex, thickly, finely punctate, and with indistinct rows of closely placed punctures, the latter 
scarcely distinguishable from those of the interstices; beneath shining, piceous, the prothorax and gula 
rufo-testaceous, the flanks of the prothorax, the metasternal side-pieces, and the epipleuree coarsely 
punctured, the rest of the metasternum and the venter very finely, sparsely punctate; legs piceous, the 
anterior femora at the base and the coxe rufo-testaceous. 
Length 33-43 millim. (9.) 
4CC 2 
