SILIS. 91 
The sides of the thorax are much rounded in the middle, narrowed a little in to the 
base, the hinder angles being turned outwards; the base and front are nearly straight ; 
but the front angles are quite lost. 
Both the specimens being females, it is impossible finally to decide on the genus of 
these specimens; but in form they approach some Discoda. The underside is black ; 
the apical segment is more shining than the rest, but is simply truncate, or has its apex 
a little sinuate, and presents no especial character. 
Subfam. SZZLINT. 
This group corresponds to the “ Siliaires” of Mulsant. At present I adopt it only 
for such genera as have the thorax with notched or deeply lacerated sides in one or 
both sexes, the hind angles cut away or in some mode defective in the males, the 
antenne more or less serrate, and the claws simple or only with a small laminar 
enlargement near the base of the outer ones. 
A more extended examination of African and Eastern forms will, I think, show that 
the longitudinal division of the apical ventral segment of the males is a character 
of the highest importance in the formation of natural divisions of this family. In this 
respect the Central-American species of Sil/és are obviously allied to my genus Discodon 
and to Leconte’s genus Polemius, which only differs from it in not having split claws. 
And if this be taken as indicating their true affinities, there are representatives of the 
Silini in Africa, Madagascar, Sumatra, and China. 
SILIS. 
Silis, Latreille, Régne An. ed. 2, p. 471 (1829). 
Ditemnus, Leconte, Class. of Col. of N. Am. p. 189. 
I have been very much in doubt as to the limits to assign to this genus; and I now 
include in it only such insects as in the males have the thorax with some incision or 
sinuosity near the hind angles, and at the same time have the last abdominal plate 
cleft and simple claws. Leconte’s genus Polemius (Lacord. Gen. des Col. iv. p. 359 ; 
Trans. Ent. Soc. Amer. ix. p. 55) approaches nearer Discodon; but I have not yet 
seen it. 
Two species of Silis are known in Europe. About twenty other species are referred 
to it from Eastern Asia, the United States, and South America. 
Section I.a. Maris prothorax juxta angulos posticos vel sinwatus. vel excisus. 
1. Silis lycoides. (Tab. V. fig. 21.) 7 
Atra, opaca; prothoracis lateribus humerisque flavis: elytris fortiter costatis ; antennis medio incrassatis, 
serratis. Long. 9-10 millim. <¢? @. 
Mas? prothoracis lateribus antice angustatis, trisinuatis. 
Femina prothorace latiore, lateribus rotundatis, ante angulos posticos minute sinuato-excisis. 
N 2 
