290 SUPPLEMENT. 
the sexes. There is a pale variety of this insect which only differs in the fuscous parts 
being all very faintly expressed. 
The characters of this species are, so far, only negative, and it can only be regarded 
as at present unclassified. The specimens are probably all females, and perhaps those 
of a Chauliognathus; but the legs are very short for a species of that genus. The 
system of coloration is like that of C. histrio. 
About forty specimens were collected, chiefly on the Volcan de Chiriqui.. 
SILIS (p. 91). 
Silis lycoides (p. 91). 
To the localities given, add:—Mexico, Toxpam, Cordova (Sallé); GUATEMALA, 
Sinanja valley, Cerro Zunil (Champion). 
Var. Elytris ferrugineis, sutura basi nigra. 
Hab. Mexico, Cordova (Sal/é). 
The specimen described and figured is a female, and not, as 1 thought possible, a 
male. A much more extended acquaintance with the species of this genus found in 
Central America enables me to state that I now believe that S. premorsa is the male 
of this species. All the specimens recorded by me as S. lycotdes are females, although 
differing in the degree of sinuation of the lateral margins of the thorax, and varying in 
other characters. The type of S. premorsa is a male from Cerro Zunil; I have seen a 
female from the same locality, and this determination may therefore be considered 
highly probable, and is confirmed by a male specimen of a Si/is from the valley of the 
Sinanja, which appears to be also that of S. lycoides. If this surmise proves correct, 
the latter is the name that should be adopted. 
The specimens quoted from Mexico, and those from Capetillo, Duefias, and Cubil- 
guitz, are to be removed from S. lycoides, the only females which I have seen being 
from San Gerdénimo, Purula, and Cerro Zunil. There is a variety, however, of a 
female from Cordova, Mexico, with yellow elytra, which, I think, should be assigned to 
this species. The other specimens are referable to S. varians. The assignment of the 
right females to the males is a difficult problem, even to the collector, as different species 
frequently occur together; and the student of this group must beware of confounding 
females of species of Discodon with those of Silis. Discodon histrio, occurring in the 
same localities, is very likely to be mixed with both this species and S. varians, but 
may be known, inter alia, by the nick of the edge of the prothorax being some little 
way above the hind angles, which are themselves entire; and this nick is visible asa 
faint plication in the female. 
S. lycoides, in both sexes, may be at once known from S. varians by the antenne not 
being compressed ; the joints are round and cylindrical; in the male some of the inter- 
mediate joints, as the sixth to the eighth, have an impressed line, as in some European 
Telephori. 
