STETRASTOMA.—ACANTHODERES. 139 
carina discoidali partim obsoleta, supra inequalibus velut undulatis, apice acute rotundatis ; antennis (¢) 
quam corpus dimidio longioribus, filiformibus, scapo (apice extus tumido) griseo-fusco, cateris articulis 
apice nigris 4--1]™ basi canis; sternis latis, planis ; femoribus intermediis longissime pedunculatis, apicee 
abrupte clavatis. 
Long. 7z lin. oC. 
Hab. Mexico, Puebla (Sallé). 
This singular species comes nearest in some of its characters to S. depressa. I have 
seen only a single example, in M. Sallé’s collection. 
ACANTHODERES. 
Acanthoderes, Serville, Ann. Soc. Ent. Fr. 1835, p. 29; Lacordaire, Gen. Col. ix. p. 753. 
Psapharochrus, Thomson, Syst. Céramb. p. 19; Lacordaire, Gen. Col. ix. p. 750. 
Symperasmus, Thomson, Syst. Céramb. p. 19. 
About sixty species of this genus are known, nearly all from Tropical America, a few 
only existing in temperate latitudes in North America, Europe, and Northern Asia, and 
in Tropical Western Africa. Notwithstanding the considerable diversity among its 
species in important points of structure, or rather in consequence of this diversity, which 
is too abrupt and irregular for systematic purposes, it is impossible satisfactorily to divide 
the genus. At any rate the division into the two genera sanctioned by the high autho- 
rity of Lacordaire seems to me impossible to be maintained, one of these two genera 
-(Psapharochrus) comprehending forms like the European A. varius and the South- 
Brazilian A. cylindricus, melanostictus, &c., which are among the most disparate the 
old genus contained. One of the results of the narrow definitions which Lacordaire 
- was induced to impose, as he confessed, is that some species are left out altogether, 
without generic location ; and, in fact, if the genus is disintegrated, nothing less than 
a very minute subdivision will satisfy the sense of natural grouping. For this there 
is no adequate reason, as the genus, in the aggregate, is well defined and easily to be 
recognized. 
1. Acanthoderes rubripes. 
Acanthoderes rubripes, Bates, Trans. Ent. Soc. 1872, p. 208. 
Hab. Nicaracua, Chontales (Belt). 
9. Acanthoderes levicollis, (Tab. XI. fig. 5.) 
Acanthoderes levicollis, Bates, loc. cit. 
Hab. Nicaraeva, Chontales (Belt). 
This and the preceding species would be typical Acanthoderes according to Lacordaire, 
being closely allied to A. daviest and A. swedere. They differ, however, very considerably 
from A. swedert in the structure of the antenne, the third and fourth joints being 
t 2 
