COpEOPTERA. I^g 



Arcopagus, Leach. 



Where, on the contrary, the second joint of the antennae is much 

 more slender than the first, and where the latter is even sometimes 

 dilated * 



There the maxillary palpi are sliortcr than the head and thorax 

 taken together ; the fourth joint at least is short or but slightly elon- 

 gated, and ovoid or triangular. 



Ctenistes, 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 antennae is 

 much larger than the preceding ones, and somewhat oval. The tho- 

 rax forms an elongated and truncated cone f . 



Bryaxis, Leach. — Euplectus, Tychus, 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 roimded :|:. 



In the last of the Pselaphii we observe this peculiarity — their an- 

 tennae consist of but six joints, or even one. They form the genus 



Claviger. 

 Claviger proper. 



Where the antennae 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 joints of the tarsi are very short; the third and last is 

 very long, Avith a single hook at the extremity. 



7"'hese 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. 



AVhere the antennae 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. glahricollis, Reich.; Ejusd., Ps. clavicornis ; Leach, lb., 80, 83, 84. 

 t Reich., Monog., p. 75, et seq. 



I See Leach, Zool. Misc. The form of the last joint of the maxillary palpi, as 

 well as the relative proportions of those of the antennae, may offer good characters 

 for division, but they do not appear to me of sufficient importance to designate ge- 

 neric sections. See the article Pselaphiens of the Encyclopedic M^thodique. 



§ See also Gyll., Insect. Suec, IV, p. 240. 



II Articerus armatus, Dalm., Insects in Copal, p. 21, tab. v, f. 12. According to 

 this figure, the tarsi are provided with two hooks. 



