488 Coleopterological Notices, V. 



to me, one of the least decisive of the 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 T\^chus 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 

 stronn: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 antennae, in having the vertexal fovess 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 COXc^. 



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

 in Cylindrarctus it is generally modified in some peculiar n)anner ; 

 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. Raffray in considering 

 Cylindrarctus a genus distinct from T3"chus. 



The known species may be thus distinguished: — 



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

 with a deep indefinitely limited impression, which is acutely angulate 

 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 rounded within behind the middle, 

 not at all angulate. 

 Basal joint of the antenn?e 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 lorigipalpis; pubescence rather 



shorter than usual, very coarse ainericaiillS 



Basal joint not described; pubescence shorter than in comes and crinifer : 

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



ludovicianus 

 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 COines 



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

 only known ; vestiture very long and bristling crinifer 



