150 TRICHOPTERYGIDZ. 
Head \arge, produced in front, very smooth and shining, ornamented with a few minute remote punctures ; 
eyes large and prominent; antenne moderate, yellow, with the club dusky. Thorax rather small, trans- 
verse, very strongly contracted at the base, rather wider but not longer than the head, very smooth and 
shining, with four very indistinct equidistant foveee near the base, and two or three others equally indis- 
tinct on each side behind the middle ; the sides rounded and strongly margined ; posterior margin very short, 
depressed, and nearly straight. Scutellum very elongate, triangular, marked with a few minute punc- 
tures. Hlytra ovate, much wider than and almost twice as long as the head and thorax, widest near the 
middle, with the shoulders and apex strongly and equally attenuated, very smooth and shining, black, 
the shoulders and apex rufous, with a row of distant punctures on each side of the anterior half of the 
suture terminating in a short convergent line, the apex rather narrow and rounded; the epipleure 
unusually broad and deep. Legs rather long, bright yellow, with the tarsi very small. Underparts black, 
with the coxe, the posterior margin of the segments of the abdomen, and the whole of the terminal 
segment flavescent. 
Hab. Guatemata, Capetillo (Champion !). 
Differs from all the other species of the genus in its strangulated form and very 
shining surface. 
This remarkable insect scarcely appears at first sight to be a true Ptenidium; but 
after a careful examination I cannot discover that it differs in any anatomical character. 
It must, however, be placed the first in order, as it approaches Act¢diwm in the general 
form of its body. 
Found not uncommonly at Capetillo. 
2. Ptenidium obesum. 
Ptenidium obesum, Matth. Trans. Am. Ent. Soc. xi. p. 151°. 
Breve, obesum, validissime convexum, glabrum, nitidissimum; capite sat brevi, latissimo; oculis magnis, vix 
prominentibus ; pronoto modico, transverso, quam caput parum longiore et multo latiore, valde convexo, 
glaberrimo, nitidissimo, punctis quatuor parvis equidistantibus ad basin, et duobus ad marginem anteriorem 
notato, lateribus valde rotundatis, vix marginatis, ad media latioribus, angulis posticis obtusis; elytris 
brevibus ovatis, validissime convexis et glabris, quam caput atque pronotum parum longioribus vix lati- 
oribus, ante media latioribus, latertbus leviter marginatis, apice valde obtuso; pedibus flavis; antennis 
obscure flavis. Long. corp. 7% lin. =0°87 millim. 
Head short and broad, very smooth and shining; eyes large, scarcely prominent ; antenne short, yellow, dusky 
towards the club. Zhorax moderate, transverse, rather longer and much wider than the head, very 
convex, smooth, and shining, with four minute equidistant punctures near the base and two near the 
middle of the anterior margin; sides much rounded and slightly margined, widest near the middle; basal 
margin straight, with the angles very obtuse. Scutellum short and broad, rather abruptly acuminated 
towards the apex. Llytra short ovate, exceedingly convex, smooth and shining, rather longer but scarcely 
wider than the head and thorax, the sides slightly margined, widest before the middle, the apex very 
obtuse. Legs moderate, dark yellow. Underparts black, with the mouth and coxe piceous. 
Hab. GuateMALA, Duefias (Champion '). 
This insect differs from its allies in its exceedingly convex and short form, almost 
impunctate surface, and short antenne. 
3. Ptenidium foveatum. 
Ptenidium foveatum, Matth. Trans. Am. Ent. Soc. xi. p. 149°. 
Obtuse ovatum, piceo-nigrum, nitidissimum, valde convexum ; capite magno, lato; oculis magnis, sat prominen- 
