492 CASEY 



wide flat sensitive apex to form the floor of the shallow excava- 

 tion. In AdelostomUy therefore, the antennas are only appar- 

 ently lO-jointed but might be so considered, in view of the com- 

 plete disappearance of the eleventh within the tenth, a process 

 of withdrawal begun in Arceoschiztis and carried still further in 

 Dacoderus. The emarginate clypeus may also recall the two 

 genera mentioned, and the large mentum, wholly covering the 

 maxillae and emarginate at apex, is somewhat similar to that of 

 Adelostoma. The excavated abdominal sutures and slight trans- 

 verse fossa of the last segment, suggest some relationship with 

 the Usechini, and the well-defined epipleurag, some alliance 

 with Stenosini, but the Cltmdmin-\\k.Q body, remarkable ce- 

 phalic and pronotal fossas and contiguous anterior coxee, are spe- 

 cial characters that widely isolate the tribe from any other livmg 

 type at present known. The single genus may be rather fully 

 described as follows : — 



Body slender, depressed, glabrous ; head deeply and abruptly con- 

 stricted at base, broadl}' produced aiad subquadrate before the 

 eyes, the antennal prominences large and convex, the front 

 deeply excavated anteriorly between the prominences, the anterior 

 wall of the excavation deeply cleft at the middle, giving com- 

 munication with a large deep excavation in the rather small, trans- 

 verse and deflexed clypeus, the two sti'ongly elevated lateral lobes 

 of which, thus formed, are flattened, ciliate on their inner edges 

 and finely punctate ; this clypeus is separated from the front by a 

 transverse suture; labrum small, transverse, emarginate and ex- 

 posed; mandibles small, slender toward tip, canaliculate beneath 

 and bifid ; mentum large, transverse, semi-circularly rounded 

 posteriorly, exactly fitting the semi-circular buccal opening and 

 concealing the maxilla3, subtransverse at apex though with a small 

 deep median emargination, the ligula large, broad, densely chiti- 

 nized and sculptured, obtriangular, the palpi slender, the last 

 joint of the maxillary elongate-oval, obtusely and obliquely pointed 

 at tip ; eyes near the base of the head, coarsely faceted, elongate, 

 not divided, situated at the middle of the vertical sides of the 

 head, on a bracket formed by an extension of the under surface 

 and but slightly inclined in plane, giving no downward vision 

 whatever ; neck rather narrow, abruptly constricted ; antennae 

 stout, with transverse and submoniliform, perfoliate joints, sparsely 

 setose, the ninth and tenth joints a little larger, the third as long 

 as wide ; prothorax elongate, suboval, crossed i:iear basal third by 

 a broad and very deep sulcus, which is closed at each side by an 

 irregularly bulbiform part of the general surface, the median line 

 deeply canaliculate throughout, the canaliculation crossing the 



