ACROPTERON. 253 
ginate (sometimes thus forming a subtriangular tooth) on the inner side some distance 
before the occasionally swollen apex, in others the inner face flattened (and dull and 
slightly concave within) before the middle for a short distance. Modifications of 
these characters are, however, to be met with in the different species; in some 
they are almost or quite obsolete. The apical joint of the maxillary palpi in the 
male is broader and more triangular in shape than in the female in the species I have 
examined. 
The sexual organs of both sexes of Acropteron differ greatly from what obtains 
in the allied genera: in the male the outer horny sheath of the cedeagus is curved 
downwards at the apex, the apex itself narrowly produced and slightly swollen, 
and the intromittent organ is extruded from beneath; in the female, instead of the 
usual horizontal process, there are two long, thin, horny, vertical plates enclosing a 
central tube, the plates together forming a rather broad, flattened, slightly decurved 
ovipositor (somewhat similar to that existing in many ‘ Orthoptera’), the apex of which 
is more or less pointed. ‘This structure exists in all the species I have examined. 
The flattened process of the female is no doubt used to guide the eggs into very 
narrow crevices, probably in the bark of decaying trees; the dissection of the female of 
a species of the genus Hegemona (H. resplendens), in which the same sort of ovipositor 
exists, only even more strongly developed, shows the vaginal opening to be placed 
immediately above this. 
The different species are chiefly found in the forest-region by beating the decaying 
branches of fallen trees. The males of nine Central-American species are known to 
me; they may be identified by the following Table :— 
Posterior tibiz for a short distance flattened and feebly concave on 
theinner side before the middle . .. . . . « « « belti, langurioides. 
Posterior tibiz slightly curved, obliquely widened at the j inner apical 
angle, the outer half slightly concave within . . . «© « «= méaklini. 
Posterior tibiz shallowly emarginate on the inner side some distance 
before the apex . . . . . Le . agriloides. 
Posterior tibie with a short broad triangular tooth followed by a 
rounded emargination on the inner side some distance before 
the apex ... ve - angulicolle, calcaratum. 
Posterior tibiz with a short broad triangular tooth followed by a 
rounded emargination on the inner side some distance before 
the apex, and also widened at the inner apical angle . . . . Jlongipenne. 
Posterior tibis sinuous, unarmed. . .. - se ee mexicanum. 
Posterior tibiz almost straight, unarmed, scarcely differing from 
those of the female . . . . . . © + e+ + + # ee 6 puneticolle. 
1. Acropteron belti. (Tab. XI. fig. 11, ¢.) 
Rather broad, greenish-bronze, very shining. Head very deeply transversely excavate in front, closely, coarsely, 
and very irregularly punctured, a rather broad longitudinal space on the vertex impunctate ; eyes strongly 
