488 Coleopterological Notices, V. 



to me, one of the least decisive of tlie differential characters, for 

 there is no species in which this joint becomes fully as long as the 

 fourth, and there are several species of true Tychus which have the 

 third and fourth joints quite similar to the usual form in Cylin- 

 drarctus ; the second palpal joint is however more abruptly and 

 strong-ly clavate and with a more slender peduncle in Tychus. 



Cylindrarctus is very closely allied to Tychus, but differs in the 

 more elongate and somewhat more depressed form of the body, the 

 more elongate antenna, in having the vertexal fovege on the sloping 

 sides near the eye — and not remote from the eye and visible from 

 above as in Tychus, — and especially in the much less distant poste- 

 rior coxae. 



In Tychus the basal joint of the antennae is usually simple, while 

 in Cylindrarctus it is generally modified in some peculiar manner ; 

 in the former the male may or may not have the anterior trochanters 

 spiculate, and the last ventral is seldom foveate as in Cylindrarctus, 

 but, — in T. minor for example, — has the surface broadly concave, 

 the apex gradually deflexed to the level of the flat ventral pygidium. 

 In Tychus the second joint of the posterior tarsi is subequal to or 

 longer than the third, while in the present genus the second joint is 

 shorter than the third. Duly considering all of these differences, I 

 am therefore inclined to agree with Mr. Raflfray in considering 

 Cylindrarctus a genus distinct from Tychus. 



The known species may be thus distinguished : — 



Third palpal joint angnlate internally near the base ; sixth ventral of the male 

 with a deep indefinitelj limited impression, which is acutely angnlate 

 anteriorly at the anterior margin, the apical margin deflexed and with an 



abruptly limited semi-circular notch longipalpis 



Third palpal joint more or less broadly roundedwithiu behind the middle, 

 not at all angulate. 

 Basal joint of the antennae obliquely carinate externally at base ; sixth ven- 

 tral of the male with a deep triangular excavation, the apical angle of 

 which is at the anterior margin as in longipalpis; pubescence rather 



shorter than usual, very coarse americanilS 



Basal joint not described; pubescence shorter than in comes s^ndi crinifer ; 

 sixth ventral witli a deep circular fovea ; body larger, 1.9 mm. in length. 



ludoTicianus 

 Basal joint obliquely flattened in a large external area at base ; sixth ven- 

 tral of the male with a small transversely lunate impression just before 



the ventral pygidium COmes 



Basal joint compressed beneath, the lower margin strongly arcuate; females 

 only known ; vestiture yary long and bristling crinifer 



