82 MEMOIRS ON THE COLEOPTERA 



The body in A stratus is moderate or rather small in size, roughly 

 and unevenly sculptured and apparently glabrous under low powers 

 of enlargement. The antennae are shorter and more moniliform 

 than usual, with the third joint shorter than in any other of our 

 genera, being about twice as long as the second but not longer than 

 the first, the tenth joint spongiose only on the parts left exposed 

 by the small subimbedded eleventh joint. The labrum is mod- 

 erately transverse and sensibly sinuate. The mentum differs from 

 that of any other American genus, except possibly Stenosides and 

 Sicharbas, in completely and closely filling the entire buccal opening, 

 being contiguous also to the closed mandibles and is without trace 

 of gular pedestal, nearly as in the European Asida; the palpi are 

 moderate or rather small, with the last joint never scalene. The 

 tarsi are short but slender and there is no exposed trochantin. The 

 anterior parts are not so small in relation to the hind body as in 

 Pactostoma ( = 0loglyptus Lac.), the elytra unevenly convex, deeply 

 embracing the body beneath and with the humeral angle distinct 

 though varying in form specifically. 



The three species may be known as follows: 



Antennae broadened apically through the ninth and tenth joints. Body 

 rather narrow, only moderately convex; head transversely impressed 

 between the antennal prominences, also with a small median im- 

 pression on the occiput, the epistoma sinuato-truncate; antennae 

 a little longer than the width of the head; prothorax about a fourth 

 wider than long, the sides strongly prominent and narrowly rounded 

 at the middle, thence converging and feebly sinuate anteriorly and 

 equally converging and deeply sinuate basally, the base evenly 

 sinuato-truncate throughout, the angles right, slightly blunt, the 

 apex deeply sinuate with the angles bluntly rounded ; surface densely, 

 subgranularly sculptured, broadly, feebly concave laterally, tumid 

 medially, with the median line impressed anteriorly, exterior to 

 which there are two small impressions on each slope of the tumidity, 

 also a larger rounded impression before the scutellum, the latter 

 small; elytra three-fifths longer than wide, gradually widening to 

 apical third, the side margins with tubercles and crests, one of which 

 forms the humerus, which is exposed beyond the thoracic base; 

 surface granulate, the suture flat, feebly elevated, each elytron with 

 an uneven medial ridge, connected by anastomosing ridges with 

 the suture and curving at apical fourth to meet a sutural ramus in a 

 stronger elevation, the ridge continued thence to the apex and having 

 an acute tubercle midway; legs rather short, the very short pale 

 stout hairs abundant and conspicuous; anterior tibiae with an everted 

 and very acute spiniforrn external angle at apex. Length 11.8- 

 13.7 mm.; width 5.5-6.5 mm. Texas contortus Lee. 



