74 HYDROPHILIDA. 
this insect very distinct amongst its known allies. There is an irregular series of punc- 
tures on the middle of each wing-case, and another near the lateral margin. The 
prosternum is not carinate along the middle. . 
The unique individual from Caldera is rather smaller, and the punctuation of the 
upper surface is not so obliterated ; but I cannot venture to treat it as a distinct species. 
HELOCHARES. 
Helochares, Mulsant, Hist. Nat. Col. Fr., Palp. (err.), 1844. 
Helophilus, Muls. op. cit. p. 182. 
Philhydrus (pt.), Mun. Cat. u. p. 480. 
This genus has not been accepted by many entomologists as distinct from Philydrus ; 
nevertheless there seem to be very good grounds for its adoption. Not only is the 
mesosternum destitute of any definite lamina or carina, but the pseudo-basal joint of 
the maxillary palpus is curved in the opposite direction to what it is in Philydrus, 
the labial palpi are shorter and thicker and their joints of less cylindrical form, there 
is always a definite polished space behind the mentum, and the front of the mentum is 
more deeply and broadly hollowed or bent inwards towards the labrum. In some 
species, possibly in all, of Helochares the mentum bears a small notch at the front 
margin in the middle; but the structure of the neighbouring parts renders this 
character very difficult of verification. 
Helochares has numerous species in various parts of the world, including even 
Australia ; but these insects are probably less tolerant of cold than are the Philydri, 
and inhabit, as a rule, warmer regions. 
1. Helochares oculatus. 
Ovalis, subdepressus, fuscus ; antennarum basi, palpis tarsisque testaceis; nitidus, fere levigatus; palpis elon- 
gatis; oculis magnis. 
Long. 3, lat. 13 lin. 
Hab. GuaTEMALA, Paso Antonio (Champion). 
Head with subobsolete punctuation; the labrum very largely exposed; the eyes 
large. Thorax with obsolete punctuation ; but this is a little more visible, though very 
fine, on the disk. Elytra almost entirely destitute of punctuation, with a very indistinct 
longitudinal series of excessively fine punctures along the middle. Mentum covered 
with coarse curved rug; the submental area very definitely (indeed abruptly) limited 
behind, not shining, although destitute of pubescence, but covered with rugz less coarse 
than those of the mentum. Prosternum without carina or angle in the middle. 
‘Mesosternum distinctly gibbous in front of the coxe. Posterior tarsi elongate, their 
second joint very long. 
