150 Trans. Acad. Sct. of St. Louis. 
gular sutures less impressed, more approximate toward base; pro- 
thorax differing greatly in form, about as long as wide, the sides feebly 
converging from the base to the apex and slightly arcuate; apex more 
strongly arcuate than the base, the apical angles very obtuse and 
rounded, a little wider than the head; elytra slightly longer than 
wide, subparallel, two-fifths wider and nearly one-half longer than the 
prothorax, paler at the sides than on the disk; abdomen distinctly nar- 
rower than the elytra throughout. Male with the fifth ventral truncate 
at apex and unmodified, the sixth much narrower, rectilinearly trun- 
cate at tip and otherwise unmodified. Length 2.7 mm.; width 0.6 
MM. ATIZONA,..6s ccccoccccsecccccsscveccsvcescesceessSONOFiCA D. Sp. 
The female in both ochracea and simplex has the apex of 
the sixth ventral broadly angulate, with the angle more or 
less rounded. The single specimen of sonorica before me has 
the apex of the sixth ventral truncate, and, as the sexual 
modifications are so simple, it may in reality be a female, but 
in any event it is a remarkably distinct species. The con- 
cealed ligula of the seventh ventral in Lithocharis, is spatuli- 
form, narrowed toward tip, and densely clothed with silvery 
pubescence. 
The Henshaw catalogue (3rd suppl., p. 10) lists a Litho- 
charts debilis Woll. I have been unable to find any such 
species described. The debilis of Erichson (Gen., p. 625) 
inhabits Colombia and the description does not correspond 
with any of our species as given above. 
MEDONES. 
The multitude of small species of more or less monotonous 
appearance, composing this group, are rather difficult to 
classify in a satisfactory manner, owing to the fact that the 
male sexual characters are usually simple and but slightly 
varied; the genus Paramedon, however, offers a very welcome 
exception in this regard. The group is much more highly 
developed in America than in Europe, comprising the follow- 
ing nineteen genera within the limits of the United States, 
only two of which — Neomedon and Sciocharis — are certainly 
known to extend for any great distance into Mexico: — 
Gular sutures completely fused, forming a single coarse suture from the 
angulate post-mental piece to the DaS€e.eesececeecececseieeereserese 2 
