1914] Mann—Myrmecophilous Insects from Mexico 175 
The larva is very different from that of X. cava, the only one 
known in that stage, which has been described and figured by 
Wheeler (Jour. N. Y. Ent. Soc., Vol. XTX, 1911, p. 165-166) and 
closely resembles that of Lomechusa. Those which I found are 
5.5 mm. in length, yellowish-white in color, with short, feeble 
legs, no eyes, papillose antenne and shallowly impressed vertex. 
The body is slender and cylindrical, not at all depressed as it is in 
cava, with an even covering of fine erect hairs. 
The movements in life were very slow. Considering the pronotal 
structure and the larval characters sharpi should not be included 
in Xenodusa sens. strict., but more properly belongs to a distinct 
subgenus for which I propose the name Pseudolomechusa. 
Apteronina wasmanni sp. nov. 
Length 3 mm. Head broader than long, rounded at sides, occipital margin 
straight; clypeus projecting, the anterior border rounded; front broadly depressed, 
the surface concave, with a longitudinal impression extending to occiput. Eyes 
rather large, located at sides of the anterior third of head. Antenne long, the 
first joint about twice the length of the second, which is two-thirds as long as the 
third; the second joint is sharply constricted near base; fourth joint about half as 
long as third; joints 4-10 subequal in length, becoming thicker anteriorly; apical 
joint cylindrical, nearly twice the length of penultimate. Thorax not as broad as 
head, very slightly longer than broad, rounded in front and at anterior third of 
sides, posterior to which the sides are straight; posterior border straight; surface 
slightly concave, with a narrow longitudinal impression at middle. Elytra trans- 
verse, each as long as broad, together broader than thorax; sides nearly straight; 
posterior border rounded. Abdomen at base as broad as elytra, broadest behind. 
Legs long and slender. 
Body and legs subopaque, finely punctate, the punctures coarser on the elytra 
and abdomen; everywhere with fine, recumbant, silky hairs; thorax and sides of 
abdomen with longer coarse hairs. 
Color black, the antennz and legs brownish. 
Described from several specimens taken with Liometopum 
apiculatum Mayr ‘at Pachuca and Guerrero Mill. 
A. schmitti Wasmann, which lives in company with the same 
host ant from Colorado to Southern Arizona, has the head longer 
than broad, the thorax is longer in proportion to the width, the 
general form is more slender; the color is light ferruginous, except 
the gaster, which is dark fuscous. The color of the Mexican form 
of the host ant is considerably darker than that of the Arizona 
variety with which I have taken schmitti, so the beetle in each 
