■642 Goleopterological Notices^ VI. 



lO — Mesostcrnum and its parapleurse as in Anthicvis Taiiarthriis 



11 — Tarsi sliorter than the tibia?, the penultimate joint slij^htly dilated. 



IVotoxiis 



Tarsi very long and filiform, longer than the tibiie, the penultimate joint 



evenly cylindrical and not at all thicker Mecyiiotai'sus 



It is unfortunate that in tliis lineal arrangement Tanarthrus 

 lias to intervene between Amblyderus and Xotoxus, Init it would 

 be still more out of place among the genera allied to Tomoderus, 

 ■where it must otherwise be placed. 



DILAXDIITS n. gen. 



The two species separated under this name, together with 

 Formicilla, are peculiar in having the acute side-pieces of the 

 l)rosternum behind the coxse more inwardl}' prolonged than in 

 Anthicus, so that thev coalesce at or near the middle, thus closing 

 the coxal cavities. In the other genera, as I find b}' dissecting 

 numerous divergent forms, the inferior flanks of the protliorax 

 form angular inward projections behind, which are widel}' sepa- 

 rated by a deep emargination of the common coxal floor, and the 

 ^oxal cavities are consequently l)roadly open. The mesosternum 

 in this genus extends in one extremely large unbroken })olished 

 plate from side to side of the body, and is largely visible from 

 above in the reentrant humeral angle ; the prominent lateral 

 •edges of this plate bear a sparse fringe of long stitf bristling set.v. 



In the form of the head Dilandius resembles Ochthenomus to 

 a great degree, the outline being oblong-suboval, with the eyes 

 small and anterior. 



Our two species are very slender ant-like insects, distinguish- 

 able at once from Malporus and Lappus by the form of the head, 

 disposition of the elytral vestiture, and b}' the fact that the lateral 

 constriction of the prothorax extends across the dorsal surface, 

 giving rise to two convex lobes.* They may be known as fol- 

 lows : — 



Dorsal constriction of the prothorax strong; white piibescent fascia of the 



elytra oblique 1. iiiyi'niecops 



Dorsal constriction feeble ; pubescent fascia transverse 2. iiiiictis 



* In the second group of Lappus there is a large dorsal gibbosity near the 

 l)ase of the pronotum, but this is a true protuberance, and is not produced by 

 a dorsal extension of the lateral constriction; in gibbithorax and others of this 

 ^oup, there is no transverse depression before the protuberance. 



