MARONIUS.—THINALMUS. 101 
of the folded margin. The apical segment is conical, small, and truncate. The base 
of the legs is clear red; the apical half of the femora, the tibia, and the tarsi are 
blackish or fuscous. The basal joint of the tarsi of the posterior legs is as long as the 
rest taken together. The wings are fuscous black at their apices, paler and more reddish 
at the base. 
Of this curious insect four examples were collected by Belt and one by Janson at 
Chontales; Champion met with a single specimen at Zapote ; and there were four in the 
collection purchased by the editors of this work from M. Salle. 
THINALMUS. 
Caput ut in Malthinus; oculi parvi, paulo prominentes. Antenne maris corpori longitudine squales, articulis 
tertio ad decimum ramum flabellatum a basi emittentibus; femine corpore paulo breviores, valde serrate. 
Palpi articulo ultimo vix securiformi. Elytra abbreviata, capite thoraceque longiora, apicibus distantibus. 
Ale ample, abdomen tegentes. 
This new genus may be briefly described as Mal¢hinus with the antenne in the male 
strongly pectinate, in the female serrate. In the single species which I at present refer 
- to it the basal joint of the antenna is stout, the second short and triangular, the third 
and succeeding joints as long as the basal one, each emitting from the base a lamellar 
branch which is longer than the joints and as long as the terminal joint, which, as usual, 
has no branch. The apical segments of the abdomen do not, so far as I can see, show 
any special appendages or particular structure, but are not easily observed in dried 
specimens. The ventral plate of the male appears divided or sulcate. 
1. Thinalmus pectinicornis. (Tab. VI. fig. 13.) 
Niger, epistomate, capite infra, prothorace (vitta discoidali excepta) trochanteribusque flavis; thoracis disco 
inequali, obsolete canaliculato. Long. 5-53 millim. ¢ @. 
Had. Guaremata, Cerro Zunil, Zapote, El Zumbador (Champion); Panama, Volcan 
de Chiriqui (Champion). | 
Head black above, with the front and underside yellow, opaque, closely and very 
obsoletely punctured ; at the base a fine longitudinal impressed line. Thorax smaller 
and narrower than the head, black above, with yellow sides. ‘The disk is shining, 
uneven, with a rather deep central channel with raised subtubercular sides; elytra 
black, with two or three raised lines and irregular confluent punctures, half the length 
of the body behind the prothorax. Wings dark. About a dozen specimens were taken 
at Cerro Zunil, one of which is figured. I have only seen one (a female) from Chiriqui. 
9. Thinalmus centro-lineatus. 
Niger ; ore et epistomate flavis, capite et prothorace linca mediana rufis, scutello rufo. Long.5-6 millim. ¢ 2. 
Mas antennis corporis fere longitudine, flabellatis ramis quam articulis triplo longioribus. 
Femina antennis corpore brevioribus, leviter serratis. 
Hab. GuatTeMALA, Sinanja valley ; Panama, Volcan de Chiriqui (Champion). 
