MALACODERMATA. 299 
A species from Chiacam, of which there are four or five females, and one male some- 
what doubtfully associated with them, which cannot be referred to 9. oblita, for the jaws 
are not suddenly bent as in the female of that species; it is less hairy, the antenne 
have not the pale apical joints, and are, moreover, shorter, with shorter | joints. 
The male, which is from the same locality, is paler in colour, with a brighter orange- 
coloured thorax, the margin of which projects in front of the nick, but yet not as in 
S. paupercula. 
9 (r). Silis paupercula. 
Sordide nigro-fusca, sericeo pubescens; ore et epistomate, prothorace (vitta mediana excepta), antennarum 
basi, elytrorum sutura et margine laterali pedibusque pallide-testaceis. Long. 5 millim. ¢ 9. 
Mas. Prothorace, margine laterali antice tuberculari plicato, in medio oblique constricto. 
Hab. Gouaremata, San Juan in Vera Paz (Champion); Panama, Bugaba, Volcan de 
Chiriqui 2500 to 4000 feet (Champion). 
Var.? Prothorace nigrescente, limbo laterali pallido. 
Hab. Panama, Volcan de Chiriqui 4000 to 6000 feet (Champion). 
There are a series of little species, of which this is one, occurring together and very 
difficult to separate from each other; I distinguish S. paupercula by the thorax in the 
male being formed very much like that of S. pauwil/a, and it may perhaps be necessary 
eventually to remove it with that species toa new genus. The thorax is not orbiculate, 
and not “nicked,” but viewed from behind with the body towards one, the front part of 
the margin projects on each side; this character will separate it from Stlis lineata. The 
head is wide with projecting eyes; the antenne two thirds as long as the body, free 
from the erect pile observable in those of S. oblita and S. ardua, and their second joint 
more than half as long as the third. 
The variety almost exactly simulates Photinus diurnus, which occurs on the Volcan 
de Chiriqui at various altitudes up to 8000 feet, and it is remarkable that in this 
variety the antenne are wholly fuscous, as they are in the Photius, and the tibie and 
under surface of the body are also dark. I have often had occasion to remark that the 
varieties of many species, which occur either in higher latitudes or in higher altitudes, 
tend rather to melanism than those which from living in hotter regions are perhaps 
forced to seek the shade more, and hence from living in retirement, in rolled-up withered 
leaves of fallen trees, or in chinks and holes during the hot sunshine, are simply brown 
or even white. The brown species of Chauliognathus, Mr. Champion informs me, have 
this habit of secreting themselves in dried leaves of a similar tint. 
9 (cg). Silis amicula. 
Nigro-fusca; antennarum articulo basali, ore, epistomate, prothorace, pedibus (tibiarum apicibus tarsisque 
exceptis) elytrorumque sutura et margine laterali testaceis ; abdomine segmentis singulis pallide marginatis, 
segmento apicali testaceo. Long. 43-5 millim. ¢ Q. 
2Q2 
