MALACODERMATA, 295 
Though I have only seen one specimen, a male, of this species at present, I have no 
hesitation in pronouncing it distinct—the chief characters being its black head and 
long antenne ; the very short second joint of the latter (which is here not longer than 
it is broad), but especially the position of the nick formed by the plication of the margin 
of the thorax, which in this and in S. atripennis is placed nearer the hind angle than in 
S. hematodes. 
5 (z). Silis aurita. 
Atra, parum nitida; capite, prothorace et scutello rufis; prothoracis margine laterali postice Jamina submar- 
ginali, parum ampliato; elytris creberrime punctatis, substrigosis. Long. 53 millim. 9? 
Hab. Costa Rica, Volcan de Irazu (Rogers). 
This species, of which there are only two specimens which I can with certainty 
assign to it, is certainly distinct from any of its allies here described, but it is very 
difficult to define the differences in such a manner as to cause it to be easily recognized. 
The head and thorax are bright red; the antennz black, their second joint about half 
as long as the third; the thorax has a tumid convexity on each side of the central 
depression, and it appears narrowest in front, owing to the margin being plicate and 
thickened behind. There are two other specimens from Irazu taken by Rogers which 
may belong to this species, but which have the thorax nearly quadrate, without any 
process ; these have the scutellum black, but as I cannot determine their sex I prefer not 
giving any decided opinion upon them; they are more nearly allied to S. appendicularis, 
with which the present species has clearly some affinity as well. 
5 (c). Silis transfixa. 
Nigra ; capite, antennis, palpis, prothorace, scutello, et coxis anticis, lete aurantiaco-rufis; coxis intermediis et 
posticis ad apices, trochanteribus, tibiis tarsisque flavis ; elytris subopacis, confertim coriaceis, undique 
tuberculis minutis seriatim ornatis, vel nitidulis, crebre subrugulose-punctatis. Long. 54-83 millim. g 9. 
Mas. Prothorace suborbiculato, infra medium oblique inciso. 
Hab. Panama, Volcan de Chiriqui 4000 to 6000 feet (Champion). 
This species is allied to 8. hwmatodes, but differs in many respects ; the head is wider, 
and the antenne and all the other cephalic appendages are red. The thorax of the 
female is more oblong and is obliquely constricted on the sides; that of the male 
appears to present a curved thin acute spine on the anterior side of the nick, but this 
cannot always be seen. The legs are black, with only the extreme base red ; usually 
only the front pair have any part of the femora red. 
A small series was secured by Mr. Champion. 
5 (p). Silis fulvipes. 
Flavo-testacea, parum nitida; elytris griseis; pectore abdomineque infuscatis, segmentis apicalibus fulvis. 
Long. 53 millim. ¢ Q. 
Mas. Prothoracis lateribus minute incisis, segmento septimo veutrali fisso, pygidialis apice angulariter exciso. 
