304 SUPPLEMENT. 
18. Silis analis. 
Nigra, tenuiter griseo-pubescens ; ore testaceo, maris abdomine ad apicem rufo, antennarum articulo secundo 
quam tertius dimidio breviori. Long. 5 millim. ¢ Q. 
Mas. Prothoracis margine laterali antice incrassato, pone medium oblique constricto ; pygidio inflato cum seg- 
mento ventrali fisso et genitalibus rufis. 
Femina, Abdominis apice summo tantum rufescente. 
Hab. Mexico, Puebla (Salié). 
About the size of Discodon cinereum, wholly black above, with the exception of the 
mouth which is whitish. Head hardly so wide as the thorax, opaque, not suddenly 
contracted behind the eyes; basal joint of the antenn very stout, second joint not 
very short, but half as long as the third. Thorax quadrate, the whole of the margin 
reflexed in the male; the thickening of the side commences a little below the front 
angles, where the margin is more reflexed and projects, till interrupted by the plica ; 
hind angles a little prominent and thickened. The convex swelling of the pygidium 
in this species is remarkable, and its red colour will cause it to be easily recognized. 
Two males and one female in the Sallé collection. 
19. Silis appendicularis. 
Statura et summa similitudine Silidis paucille. Nigra, parum nitida; capite prothoraceque rufis, illo basi 
et occipite nigro; elytris perobsolete subtiliterque rugose-punctatis, fere coriaceis. Long. 4-43 millim. 
32. 
Mas. Prothoracis margine laterali paullo ante angulos posticos lamina obliqua dentiformi instructo, segmento 
ventrali septimo fisso. 
Femina. Prothoracis margine laterali pone medium elevato plicato, segmento ventrali apicali minute exciso. 
Hab. Panama, Volcan de Chiriqui 4000 to 6000 feet (Champion). 
The extreme likeness of this insect to S. pausilla renders a repetition of the general 
description of that insect superfluous. The structure of the thorax is different in both 
sexes. At present I have only found one example which I can certainly assert is a male ; 
in this the plicate margin of the thorax runs into a lamina-like appendage close to the 
hind angles; this structure is quite different from that of S. pauailla. The other differ- 
ences are minute but quite sufficient ; the elytra are more finely sculptured, more black 
and shining, and the thorax is not black near the front margin. 
It would appear to frequent a higher altitude than the S. pauailla, but there are a 
few specimens of that species, of a variety with a red head, which appear to have been 
found in company with this insect, and these render its discrimination the more 
difficult. 
I have as yet seen only six specimens of this species. 
20. Silis pauxilla. 
Atra, parum nitida; ore, epistomate, antennarum articulo basali subtus, prothoraceque rufis, hoc margine 
antico nigrescente. Long. 33-4 millim. ¢ 2. 
