MALACODERMATA. 297 
This species is a very close ally of S. lineata, and is perhaps not quite satisfactorily 
distinguished from it. It is, however, in the male characters that the chief difference 
lies, the thorax in the present insect being of the form of the species of Section I. 8, in 
which I have placed S. lineata. But in the typical males of S. dineata the thorax 
is not orbiculate, but is doubly notched, and has the minute projection at the hind 
angles which is found in the first Section of this genus, and rather resembles that of the 
first Section of Discodon. In addition to this sexual difference S. lineola is a narrower, 
more shining, and less pubescent insect; it has never wholly yellow elytra as have the 
Chiriqui specimens of S. lineata; and the antenne have not the yellow apical joints. 
9 (x). Silis oblita. 
Nigro-fusca, nitida, pilosa ; ore, antennarum articulis tribus vel quatuor ultimis, prothorace pedibusque pallide- 
testaceis, his tibiis tarsisque anticis, illo vitta discoidali, plerumque ad basin tantum distincta, nigricanti- 
bus. Long. 6-7 millim. ¢ Q. 
Mas. Oculis magis prominulis ; prothorace suborbiculato, margine antice sinuato, infra medium plicato, minute 
inciso, angulo postico leviter producto. 
Femina. Mandibulis fortiter curvatis ; prothorace antice rotundato, lateribus leviter bisinuatis. 
Hab. Panama, Volcan de Chiriqui 2000 to 6000 feet, Bugaba, Boquete 4200 feet 
(Champion). 
Head black ; mouth and antenniferous tubercles pale ; palpi fuscous, pale at the base ; 
eyes moderate, subglobular in the male, rather prominent in the female, owing to the head 
being suddenly contracted behind. Antenne fuscous or black, with three, sometimes 
four, nearly white joints at the apex: they are pubescent, with erect hairs, a character 
which will separate this species and S. ardua from S. paupercula; their second joint short, 
not so much as half of the length of the third joint, but not so short as in S. ardua ; in 
the males this joint isnot more than one third of the length of the third joint. Thorax as 
in males of Section I. B, but with the plication and sinuation minute ; it is nearly the same 
as in S. ardwa, and very different from that of S. paupercula; in the female it is trans- 
versely subquadrate, the anterior angles rounded, the sides faintly bisinuate with a minute 
anterior callosity, the hind angles right-angles, with a minute production of the basal 
margin. Elytra finely, subrugosely, and very closely punctate, only showing faint 
indications of longitudinal lines; black with a grey, almost violet tint; occasionally the 
shoulder has the callus slightly pale. Legs, including the coxe, testaceous, but the front 
tibiee and all the tarsi at their claw-joints are fuscous. ‘The apex of the abdomen is pale. 
This is one of the most difficult species in this group to make out ; closely resembling 
as it does several others, attention must be paid, in the first instance, to the relative length 
of the second joint of the antenne and their pubescence, characters which separate a 
little group of the genus. The bent mandibles of the females I have as yet only 
observed in this species and S. ardua, but it will probably be found in some others. 
S. nigrita is difficult to separate, the males being very close to those of this species. 
I have seen single specimens of an insect probably identical with this species from 
BIOL, CENTR.-AMER., Coleopt., Vol. III. Pt. 2, Aprid 1885. 2Q 
