TROPISTERNUS. 57 
recognized by its small or rather small stature, by the absence of swimming-cilia on the 
hind tibiz, by the short, or rather short, middle and hind legs, which are armed with 
numerous and conspicuous spines, by the epipleural margin being punctate from the 
shoulder to near the extremity, and by the rather large size of the pubescent area at 
the base of the hind femora. The variation in the Central-American individuals is 
considerable; but I have been unable to detect any constant characters indicative of 
there being more than one species. 
8. Tropisternus ovalis. (Tab. II. fig. 5.) 
Tropisternus ovalis, Cast. Hist. Nat. ii. p. 54°. 
Hab. Mexico, Vera Cruz (Hége); GuatemMata, Paso Antonio 400 feet (Champion).— 
Sout America, Colombia, Brazil t. 
This species is an easily recognized one, and may readily be distinguished, 
independently of the small stature and peculiar form of its individuals, by the greater 
elongation of the sixth, or ear-like, joint of the antenna, and its shorter sternal spine. 
It varies a good deal in colour. A specimen from Paso Antonio is figured. 
9. Tropisternus concolor. 
Ovalis, latiusculus, posterius haud acuminatus, nitidissimus, subtilissime punctulatus, niger (interdum superne 
subsenescens); pedibus posterioribus brevibus, ex parte majore nigris, tibiis ciliatis; margine epipleurali 
a basi fere ad apicem punctato; carina sternali levigata ; abdominis apice ecarinato; femoribus basi parum 
late pubescente. 
Long. 4—5, lat. 23 lin. 
Hab. Mexico, Guanajuato (Dugés, coll. Sallé), Parada (Sallé), Oaxaca (Hége), 
Hacienda de Bleados, San Luis Potosi (Palmer); GUATEMALA, Guatemala city 5000 feet 
(Champion); Costa Rica (van Patten). 
Mentum quite sparingly punctured. Base of antenne and palpi yellow, the tip of 
the latter dusky. Upper surface very shining, very feebly punctate, so that on 
the wing-cases scarcely any punctuation can be detected. Sternal carina almost 
impunctate. Apex of the hind body without any carina; but there exists a 
perceptible elevation bearing two or three minute hairs. Legs black, but the 
femora marked towards the extremity with yellow, and the upper face of the tibie 
sometimes with a yellow streak; the front tibiz nearly or entirely yellow. 
The species is allied to the South-American 7. nitidulus, Brullé ; but that insect is of 
feebler build, with more slender legs and smaller head, and has the upper surface more 
distinctly punctulate. ; 
10. Tropisternus chontalensis. 
Latus, parum convexus, posterius haud attenuatus, nitidissimus, niger vix metallice micans, subtilissime 
punctatus ; pedibus gracilibus, piceis, anterioribus ex parte majore testaceis, femoribus posterioribus rufo 
signatis ; margine epipleurali anterius impunctato, posterius angusto crebre punctato; spina metasternali 
BIOL, CENTR.-AMER., Coleop., Vol. I. Pt. 2, October 1882. IT 
