300 SUPPLEMENT. 
Mas. Prothoracis margine laterali antice plicato-sinuato, lamina parum prominula instructo. 
Femina. Prothoracis margine laterali antice sinuato, leviter plicato. 
Hab. Panama, Bugaba, David (Champion). 
Head black, with the exception of the mouth and underside ; antenne very slender, 
not so long as the body, usually fuscous, with one or two joints pale at the base, or pale 
and becoming infuscate in the last four or five joints. ‘Thorax reddish yellow, paler at 
the margins; quadrate in the male, transverse in the female. Legs pale; tibie and 
tarsi infuscate, the former sometimes pale. Elytra dark fuscous, slightly shining, 
margined with pale (almost white) testaceous, except at the base. Sides of the abdomen 
and each segment at its apical margin almost white ; the apical divided segment in the 
male reddish yellow. 
This little species is near S. paupercula (in colour it approaches S. albicincta), but it 
is more parallel in form and less vividly coloured than that species. The plication 
of the thorax is different, and more like that of Plectonotum; but the hind angles 
are not cut out, they are nearly rectangular; nor is the margin reflexed or thickened, 
excepting at the point where the fold takes place. 
Eight specimens, all from Bugaba. 
9 (x). Silis nigroplectrum. 
Nigro-picea, nitida ; prothoracis elytrorumque marginibus albis, abdominis segmentis singulis pallide marginatis ; 
pedibus piceis, genibus pallidis. Long. 4 millim. 9. 
Femina. Prothoracis margine laterali antice plicato, plicula subtuberculari nigra. 
Hab. Panama, Volcan de Chiriqui 2500 to 4000 feet (Champion). 
There are only two females of this species, but it is clearly distinct from S. amicula, 
to which it is allied, and from which it is distinguished by its darker colour and the black 
disc of the thorax. The black fold in the margin of the thorax may of course not be 
always so coloured; but it appears to me that it probably will prove to be a good 
character, as this structure where it occurs is usually of a darker red or brown colour 
than the rest of the margin. 
9 (1). Silis chalybeipennis. (Tab. XII. fig. 18.) 
Nigra ; capite, antennis, palpis, scutello prothoraceque lete rufis; elytris nigro-ceruleis, nitidis. Long. 7-73 
millim. ¢ 9. 
Mas. Prothoracis margine laterali ultra medium plicato, angulo postico profunde exciso. 
Hab. Panama, Volcan de Chiriqui 4000 to 8000 feet (Champion). 
A very beautiful and distinct species. The head, thorax, scutellum, and antenne of 
a bright orange-red, and shining. The thorax is transversely subquadrate, with the 
front angles rounded off, the margins a little expanded and elevated; the anterior 
plication takes place a little behind the middle, the part below being a little thickened. 
