110 HYDROPHILIDA. 
Hab. Mexico, Cordova, Teapa (Sall/é); GuatTemaLa, Cerro Zunil 4000 feet, Tamahu, 
Senahu, Chacoj, Zapote, and San Geronimo (Champion). 
The punctuation of the head and thorax is coarse and rather close; the strie of the 
elytra are deep and distinct, even the internal striz are deep at the base ; the strie are 
punctate, but not coarsely, the interstices are rather closely and distinctly punctate. 
The legs are short and stout, strongly spinulose ; the mentum is small, with a definite 
notch in front, and its surface is shining, with some rather coarse punctures about the 
base; the prosternal carina is moderately strongly elevated; the mesosternal central 
piece is rather narrow for this genus, and is coarsely punctate. 
The species is readily distinguished from P. lafertei by its smaller size, more oblong 
and less convex form, coarser sculpture, shorter legs, and by some slight but good 
structural characters, the central piece of the mesosternum being narrower, and the 
mentum small, with a more definite notch in front. Like its allies it varies a good deal 
in size and the depth of the colour, and a little in the coarseness of the sculpture. 
3. Pelosoma prosternale. 
Ovale, convexum, nitidum, supra nigro-piceum, elytris apice late rufo, subtus piceum; pedibus, antennis 
palpisque testaceis ; capite thoraceque sat crebre et fortiter punctatis ; elytris haud striatis, sed subtiliter 
seriatim punctatis, interstitiis sparsim punctulatis; prosterno in medio altissime carinato, carine facie 
inferiore rotundata. 
Long. 14, lat. 2 lin. 
Hab. Mexico, Guanajuato (Dugés, coll. Sallé). 
This species has completely the appearance of a Cercyon; but the generic characters 
are fully those of Pelosoma, and in addition it presents a structural character peculiar 
to itself: viz. the prosternal carina is very strongly elevated; butits greatest prominence 
is not in front, but in the middle; hence it presents below a rounded outline, and forms 
no angular prominence in front, as it does in the other species of the genus. The 
series of fine punctures that replace on the elytra the usual strize are very even and 
regular, the punctures being throughout of one size; and even at the apex the series are 
not deepened into strie. On the under surface the prosternum and ventral segments 
are obscure reddish in colour, the breast being darker. 
4, Pelosoma carinatum. 
Ovale, convexum, supra piceum, elytrorum apice rufescente, nitidum, subtus rufescens ; antennis, palpis pedi- 
busque testaceis; capite thoraceque crebre fortiter punctatis ; elytris substriatis, striis subtiliter punctatis, 
interstitiis sparsim subtilius punctatis; prosterno in medio altius carinato, carine facie inferiore recta, 
anterius angulatim prominula. 
1 5}; 
Long. 14, lat. 3 lin. 
Hab. GuatemaLa, San Gerdénimo (Champion). 
This insect is extremely similar to P. prosternale, although the prosternal carina is 
very different: this is strongly elevated ; but its lower edge is straight and projects in 
