HELOPS. 313 
Diastixus, Allard, Rév. Hélopides, L’Abeille, xiv. p. 5; Mittheil. der schweiz. ent. Ges. v. pp. 17, 
43, & 174*, 
For the purposes of this work I retain the genus Helops solely for certain apterous 
species, most of which belong to Coscinoptilix, Stenomas, or Diastivus as defined by 
Allard. I do not feel justified in adopting any of these generic names for the Central- 
American species. To do so it would be necessary to make others, not only in Helops, 
but in Tarpela and Nautes, and this, in the present state of our knowledge of the 
“Helopides” of tropical South America (a single species only of the group has been 
described as yet, Nautes ovatus, F. Bates, from Colombia), I am not prepared to do. 
In Allard’s ‘ Révision’ no mention is made of the presence or absence of wings, the 
presence of which often denotes more prominent humeri, a longer metasternum, and 
a longer scutellum. 
a. Epipleure narrowly extending to the apex of the elytra. 
1. Helops gracilicornis. (Tab. XIII. fig. 21, 2.) 
Coscinopter gracilicornis, Allard, Rév. Hélopides, L’Abeille, xiv. pp. 15, 52°. 
Coscinoptilix gracilicornis, Allard, Mittheil. der schweiz. ent. Ges. v. pp. 33, 127°. 
Hab. Muxico? (colls. Oberthiir, F. Bates, Mus. Brit.), Orizaba (mus. Belg.!), Jacale 
(Sallé). 
9. Helops cavifrons. (Tab. XIII. fig. 22, 2.) 
Elongate ovate, moderately convex, metallic bronze, the prothorax more shining and of a greenish-golden tint. 
Head very sparingly and finely punctured, the epistoma truncate in front and limited behind by a deep, 
broad, transverse furrow ; antennee (female) rather long and slender, joints 9 and 10 subequal, and scarcely 
widening outwardly, the apical joint longer than the tenth, ferruginous; prothorax rather narrow, as long 
as broad, moderately longitudinally convex, widest before the middle, very finely and narrowly margined, 
the sides feebly sinuate, and very slightly narrowing behind and scarcely narrowing in front, the apex 
straight (when viewed from above), the anterior angles rounded and deflexed, the base broadly truncate 
in the middle and rather obliquely cut off at the sides, the basal foveze deep, a shallow transverse impres- 
sion just within the basal margin in the middle, the hind angles rather obtuse, the surface sparingly and 
finely punctured, the punctures a little coarser and closer at the sides; elytra long, widest beyond the 
middle, slightly rounded at the sides, obliquely narrowing at the shoulders, the latter rounded, the base 
truncate, with rows of shallow, irregular, distantly placed, rounded or elongate impressions, the impressions 
fine on the disc, and shallower and still finer at the sides and apex, the interstices flat and almost impunc- 
tate, the apices a little produced, impressed within, and separately rounded ; legs slender, ferruginous ; 
beneath slightly shining, brownish-zneous, very shallowly and finely wrinkled, and indistinctly punctured, 
the flanks of the prothorax almost smooth ; prosternum strongly declivous. 
Length 13} millim.; breadth 5 millim. (@.) 
Hab. GuatEMata, Totonicapam 10,000 feet (Champion). 
This species is allied to H. gracilicornis, but differs in having the head smoother ; 
the thorax longer and narrower, more parallel-sided, very much more finely and 
* The synonymy referring to the New-World species only is quoted. 
BIOL. CENTR.-AMER., Coleopt., Vol. IV. Pt. 1, August 1887. 2SS 
