STENUS. 649 
Head very broad, excavate, closely punctate, with a short, broad, shining space on the 
middle of the vertex. Thorax rather longer than broad, the sides in front dilated and 
rounded, very densely rugose-punctate. Elytra broad, scarcely longer than the thorax, 
coarsely and closely rugose-punctate. Hind body shining, black, only finely margined ; 
the basal segments coarsely but sparingly, the apical segments very obsoletely and 
very sparingly, punctured. Tarsal lobes slender, very elongate. Male with the 
middle tibie minutely mucronate at the apex internally; hind legs with the femora 
a little dilated, the trochanters slender, elongate, and free at the extremity, the tibie 
mucronate internally a little distance above the apex; fourth and fifth ventral segments 
depressed along the middle and feebly emarginate behind, the sixth deplanate and finely 
punctate along the middle, the seventh with a moderately large simple excision. 
I have preserved the name with which this species was ticketed in Sallé’s collection. 
The examples from Guatemala have the elytra slightly shorter than in those from 
Mexico. The species is apparently rare, as we have received only a dozen examples. 
21. Stenus trochanterinus. (Tab. XVII. fig. 8, 3.) 
Niger ; antennis, palpis pedibusque testaceis ; prothorace elytrisque dense, fortiter profundeque rugosis ; abdo- 
mine basi parce punctato, apice fere impunctato. 
Long. 7 millim. 
Hab. Panama, Volcan de Chiriqui 2000 to 4000 feet (Champion). 
This species is very closely allied to S. scabrosus, but the sculpture of the thorax and 
elytra is still rougher, so that it does not appear atall like punctuation. ‘The structure 
of the legs in the male is similar to that of S. scabrosus, but the terminal ventral 
segment has a deep elongate excision, the sides of which are reflexed, the notch being 
preceded by a deep depression, becoming narrower in front, and extending nearly to 
the base of the segment. 
We have received a good series of this remarkable Stenus; the specimens do not 
exhibit any variation. 
22. Stenus scabripennis. 
Niger ; antennis, palpis pedibusque testaceis ; prothorace elytrisque dense profundeque rugoso-punctatis ; abdo- 
mine fortiter punctato. 
Long. 55 millim. , 
{| 42ab. Mexico, Jalapa, Cordova (Hége); GUATEMALA, near the city, San Gerdnimo, 
Capetillo, Panima in Vera Paz, Cubilguitz (Champion); Panama, Bugaba (Champion). 
This insect also is very closely allied to S. scabrosus, but besides being smaller, may 
be readily distinguished by other characters: the thorax is considerably shorter, not at 
all longer than broad; the sculpture of the thorax and the elytra, though rugose and very 
dense, is finer ; the punctuation of the hind body is more conspicuous, and on the apical 
segments less obsolete ; the legs are shorter, and the trochanters in the male are not 
BIOL. CENTR.-AMER., Coleopt., Vol. I. Pt. 2, December 1886. 4 00 
