HETERYON.—CERCYON. 108 
HETERYON. 
Corpus suboblongum, depressum; labrum exsertum valde transversum. Antenne 8-articulate, articulis tribus 
ultimis clavam elongatam sat compactam formantibus. Palpi maxillares parum elongati, articulo secundo 
leviter elongato. Prosternum anterius in medio valde angulariter prominulum. Mesosternum in medio 
ante coxas carina humili munitum, carinula hac anterius angulo parvulo disjuncto. Abdominis segmen- 
tum basale ecarinatum. Tarsi parum elongati, rigidi, quinquearticulati, posteriores articulo basali quam 
sequens crassiore, sed parum longiore. 
Although the characters of the obscure little insect for which I propose this name 
are somewhat anomalous, there can, I think, be no doubt. that it should be placed at 
the commencement of the Cercyon group of genera. It has the appearance of a small 
Dactylosternum, but the exserted labrum and the peculiar armature of the mesosternum 
are more like what we find in the Hydrobiini. The mesosternum has in the middle an 
elongate but very slightly elevated longitudinal carina, and in front of it a slightly more 
prominent angle; this is similar to what exists in the genus Berosus, except that the 
development is less. The two individuals examined have been in very dirty condition ; 
but I am pretty certainly right as to the structure of the tarsi, although I am not very 
sure as to the number of the intermediate joints of the antenne; this, however, is 
unimportant, the formation of these organs being quite of the Dactylosternum type, 
with rather more compact club. 
1. Heteryon depressus. 
Suboblongus, piceus, supra nitidus, subtus opacus; antennis, palpis pedibusque testaceis; capite thoraceque 
crebrius parum fortiter punctatis; elytris striatis, striis latis, fortiter punctatis, interstitiis subitilissime 
subseriatim punctulatis. 
Long. 14, lat. 3 lin. 
Hab. Mexico, Cordova (Saldé). 
Basal joint of antenne slender, but elongate, nearly as long as the maxillary palpi; 
club elongate, its terminal joint with acute apex. Eyes small, but prominent; head 
much immersed in thorax. Thorax, like the head, shining and with a rather close, not 
coarse punctuation. Elytra with broad strie, in which are placed closely very coarse 
punctures; this sculpture extends from base to apex, and is similar throughout, except 
that the internal series are rather finer than the external; along the middle of each 
interstice are rather numerous excessively fine punctures. The mentum is large and 
broad, feebly emarginate in front, very opaque, owing to an excessively fine and dense 
sculpture, which extends also to the rest of the under surface of the head; breast and 
ventral segments quite dull, but not pubescent; femora not very broad, shining, 
scarcely punctate. 
CERCYON. 
Cercyon, Leach, Zool. Mise. iii. p. 95 (1817). 
This is an extensive genus, of about eighty species, of small palpicorns, and has a 
