AULONIUM.—ANARMOSTES. 471 
and less distinct. The great majority of the individuals can be distinguished by a 
glance at these thoracic characters. 
I assign as a variety to A. bidentatum a few specimens in which the median lines of 
the thorax are absent; I do so because we have received two or three examples that 
are intermediate in this respect. 
Chevrolat 2 thought it possible that all the American forms of this genus might 
really belong to one species; but this seems very improbable. Possibly a knowledge 
of the sexes might throw some light on the subject. I have, however, failed to find 
any distinctive external sexual characters, and I doubt very much whether the greater 
development of the thoracic elevations, thought by Horn to be characteristic of the 
male of A. longum and by Sallé? of the male of A. bidentatum, be really such ; because 
in the series before me there is no apparent line of demarcation between the characters 
in this respect. 
ANARMOSTES. 
Anarmostes, Pascoe, Journ. Ent. i. p. 110 (1860). 
This genus consists of three or four South-American species. It is misplaced in the 
Munich Catalogue, where it stands next Deretaphrus. It is really very close to 
Colydium, from which it is distinguished by the greater enlargement of the tibize 
towards the apex, and their conspicuous denticulation. 
1. Anarmostes argutus, sp.n. (Tab. XV. fig. 4.) 
Oblongo-subcylindricus, piceus, opacus, antennis rufis; prothorace elytrisque regulariter alte costatis, his 
intervallis fortiter biseriatim punctatis. 
Long. 6-7 millim. 
Hab. Nicaragua, Chontales (Belz). 
Head indistinctly rugose-punctate; epistome quite rounded at the sides, partly 
dividing the eyes. Thorax longer than broad, almost parallel-sided, but very little 
narrowed behind, front angles produced, the side-margins much raised; along the 
middle are four, very strongly raised, nearly equidistant, coste, so that the thorax 
appears sex-costate: all the coste are strongly raised quite at the front margin; the 
two median are continued quite to the base, and connected there by a feebly curvate 
transverse elevation; the lateral coste extend nearly to the base. LElytra each with 
three equal sharply raised coste, and an external fourth one not so strongly raised ; 
the intervals broad, biseriately crenate-punctate. Under surface dull, densely sculp- 
tured, the ventral segments with a remarkably developed strigose sculpture. 
The two examples obtained of this interesting species are unfortunately in an 
extremely bad state of preservation. The three South-American species described by 
Pascoe are all closely allied to A. argutus, but all four of them differ by slight 
characters of form and sculpture. 
