66 HYDROPHILIDA. 
extends in front of the eyes, so that these are not all prominent ; and it extends backwards, 
without, however, completely dividing the eyes. The antenne appear to have only seven 
joints, the first extending just beyond the margin of the clypeus, the second being rather 
large, while the third is quite minute, and the fourth is dilated and very closely applied 
to the base of the elongate, slender, loosely articulated club, which is composed of three 
joints. The maxillary palpi are short, with the apical joint a good deal longer than the 
penultimate ; the mentum is transverse, flat, rounded in front. The mesosternum is 
elevated in front of the middle coxe, so as to form a triangular margined prominence, 
connected behind with avery slender process of the mesosternum ; the middle and hind 
coxe, as also the ventral segments, are very finely pubescent; and the tarsi are quite feeble, 
with the basal joint very short. The epipleure beneath are very largely developed at 
the shoulder, being, however, completely folded in, so that a sharp edge is presented 
along the margin of the wing-case. 
1. Metacymus parvulus. 
Ovalis, valde convexus, lateraliter subcompressus, fusco-testaceus, limbo dilutiore, nitidus; antennarum basi 
palpisque testaceis, pedibus rufis; prothorace valde transverso, fere impunctato; elytris irregulariter 
punctatis, stria suturali anterius desinente, ad latera in medio seriebus duabus valde abbreviatis punctorum 
majorum. 
Long. 1, lat. 3 lin. 
Hab. Panama, Volcan de Chiriqui, 2500 to 4000 feet (Champion). 
Head extremely short and broad, very sparingly punctate. ‘Thorax extremely short, 
the angles extremely rounded, the sides much narrowed towards the front. Elytra finely 
punctate near the suture, more coarsely towards the sides, and there furnished with two 
very short series of larger punctures. 
The single individual found by Mr. Champion is in very fragile condition; the 
resemblance in colour and sculpture to the species of Anacena is considerable. 
PHILYDRUS. 
Philydrus, Solier, Ann. Soc. Ent. Fr. 1834, p. 815. 
Much difference of opinion has prevailed as to what variety of forms should be 
associated under this name; but the genus here is accepted under deduction of 
Helochares, Cymbiodyta, and Hydrocombus, which are all included among Philydrus 
in the Munich Catalogue of Coleoptera. Even when thus limited the genus will 
probably prove to be very widely distributed, but more specially characteristic of the 
temperate regions of the world. The species show everywhere such a great resemblance 
in their external appearance that it is impossible to determine them without reference 
to the structural characters. I give therefore the following indications necessary for 
the comprehension of the Central-American species :— 
