258 HETEROMERA. 
12. Acropteron brunneum. 
Acropteron brunneum, Makl. Act. Fenn. vii. p. 119°. 
Hab. Costa Rica (Wagner ').—Braziu}. 
Iam unable to identify this species among the large number of Central-American 
Acroptera before me; oddly enough, we have not received a single representative of the 
genus from Costa Rica. It seems to me very improbable that the insects from Brazil 
and Costa Rica really represent one and the same species. 
Group ISCHYOMIIDES. 
This new group is proposed for a single species, Ischyomius singularis, an insect 
inhabiting Colombia, including the State of Panama. Jschyomius differs in so many 
important points of structure from the “ Cnodalonides,” as defined by Lacordaire, that 
I find it impossible to include it in that group. Though the definition of the 
“Cnodalonides” now requires extensive modification to include the genera since 
described, still we do not find the general structure at all agreeing with that of 
Ischyomius. Certain “ Cnodalonides,” Platycrepis, have the two or three penultimate 
joints of the tarsi laterally compressed and strongly bilobed somewhat as in /schyomius, 
but the other structural characters differ greatly. The “ Ischyomiides” may very 
possibly have to be removed eventually from the family “'Tenebrionide.” 
I do not detect any external sexual difference in Jschyomius; the sexual organs are 
formed much as usual (not in the least resembling Acropteron):—in the female, a 
flattened horizontal process (which may possibly serve the function of an ovipositor), on 
either side of which and close to the apex is a rather long style; in the male, a long, 
narrow, pointed sheath. 
ISCHYOMIUS. 
Ischyomius, Chevrolat, Mitth. des Minch. ent. Ver. ii. p. 98 (1878). 
This genus was established upon a very remarkable insect from Colombia, and stated 
by its describer to be near Acropteron. The narrow elongate form, the slender antenne, 
the widely separated eyes, and the mucronate apices of the elytra bear, it is true, a 
superficial resemblance to Acropteron, but there the affinity ends, the structure of the 
oral organs, anterior coxal cavities, tarsi, &c. being wholly different. 
The following is Chevrolat’s description :— 
“ Ischyomius. Charact. generis :—Corpus elongatum, planum, apice emarginatum bidentatum. Caput latum, 
apice rotundatum, transversim posticeque sulcatum. Clypeus angustus transversalis. Labrum subquad- 
ratum emarginatum, mandibule late, plane, arcuate, acute. Ultimo articulo palporum maxillarum 
elongato-acuminato. Oculilaterales rotundati. Antenne submoniliformes, undecim-articulate, prothoraci 
eequilonge, articulo tertio longiore, 4° paullulum breviore, ultimo ovali. Prothorax subquadratus, planus, 
lateribus reflexis, postice paullulum attenuatis, angulis quatuor rectis, acutis. Scutellum rotundatum. 
Elytra basi truncata, ad apicem sensim alternata, subparallela, in angulo marginis spinosa, intus emar- 
