COLEOPTERA. 143 
Arcopacus, Leach. 
Where, on the contrary, the second joint of the antenne is much 
more slender than the first, and where the latter is even sometimes 
dilated *. 
There the maxillary palpi are shorter than the head and thorax 
taken together; the fourth joint at least is short or but slightly elon- 
gated, and ovoid or triangular. 
CrenistEs, Reich. 
These Insects are very distinct from all others of the same family, 
in the three last joints of the maxillary palpi, on the outer side of 
which we observe a point or tooth with a terminal seta; the second 
is very long, arcuated, and inflated and rounded at the end; the two 
following ones are almost globular. The last joint of the antenne is 
much larger than the preceding ones, and somewhat oval. The tho- 
rax forms an elongated and truncated cone +. 
Bryaxis, Leach—Evruecrus, Tycuaus, Ejusd. 
Where no such characters are presented by the maxillary palpi; 
their last joint is elongated and conical or securiform. The thorax 
is short, hardly longer than wide, and rounded f. 
In the last of the Pselaphii we observe this peculiarity—their an- 
tenn consist of but six joints, or evenone. They form the genus 
CLAVIGER. 
CLAVIGER proper, 
Where the antenne consist of six distinct joints. 
These Insects have no apparent eyes. The maxillary palpi are very 
short, without distinct articulations, and with two terminal hooks. 
The two first jomts of the tarsi are very short; the third and last is 
very long, witha single hook at the extremity. 
These Pselaphii are found under stones in barren localities, and 
even in the hills of certain small yellow Ants. An excellent Mono- 
graph of this genus has been published by M. Miiller, in the third 
volume of the Magasin der Entom. of M. Germar §. 
ArticErus, Dalm. 
Where the antennez appear to be composed of a single joint, form- 
ing a cylindrical and elongated club, truncated at the extremity. 
The eyes are distinct and the tarsi are terminated by two hooks |]. 
* Ps. glabricollis, Reich: ; Ejusd., Ps. clavieornis; Leach, Ib., 80, 83, 84. 
+ Reich., Monog., p. 75, et seq. 
t See Leach, Zool. Misc. The form of the last joint of the maxillary palpi, as 
well as the relative proportions of those of the antenne, may offer good characters 
for division, but they do not appear to me of sufticient importance to designate ge- 
neric sections. See the article Pselaphiens of the Encyclopédie Méthodique. 
§ See also Gyll., Insect. Suec., IV, p. 240. 
_ || Articerus armatus, Dalm., Insects in Copal, p. 21, tab. v, f. 12. According to 
this figure, the tarsi are proyided with two hooks. 
