NORTH OF MEXICO. 275 



Fort Grant, Arizona, under stones, uot common. In sculpture and the arrangement 

 of the scale-like hairs this species resembles the last, but differs in color and form of head 

 and thorax. 



A. armatus, dark brown, bead oval, rounded and narrowing behind the eyes, and suddenly narrowing to form 

 the neck, with its hind angles moderately distinct; thorax subquadrate, feebly channelled, sides feebly rounded an- 

 teriorly and slightly narrowing behind. Elytra oval, costs less distinct, interstices -lightly carinated and with two 

 rows of coarse punctures. Anterior femora armed at middle with a small acute tooth, middle femora with a tubercle, 

 posterior femora mutic. Length .l<i inch. 



One specimen. Owens' Valley, collected during October, 1862. 

 V in the preceding species, the head, thorax, edges of costae, under surface of bodj 

 and legs are sparsely covered with the yellowish scale-like hairs. 



The species of this genus seem to be becoming numerous. Doubtless others remain 

 in the unexplored desert regions of the West, to reward any one who has sufficient pa- 

 tience to find stones under which they can find lodgment, and endurance to withstand 

 the heat that has been as high as 125° Fahr. in as protected a place as possible, and 

 during the season too. when TenebrioDidae are most abundant. 



To facilitate the recognition of these species, I add the following table: 

 Femora mutic. unarmed. 



Thorax not channelled on disc. costipennis. 



Thorax with disc grooved. 



Head elongate oval, thorax much narrower behind. sulcicollis. 

 Head rotundatc-oval, thorax feebly narrowed. regular) s. 



Femora (anterior and middle) armed with a small acute tooth or 



tubercle at middle. a r m a t U s. 



f'osfqtciuiis, Lea, differs besides by having the hairs on the surface of the body darker 

 in color, and on the edges of the costae almost erect. The thorax regularly convex and 

 all the angles more distinct. The species are all nearly uniform in size, varying only 

 from .15-. 18 inch. 



TRIBE X — DACODERINI. 



Mentum large lunate, concealing base of maxilla?, ligula exposed. Middle coxa' en- 

 closed b_\ sterna, anterior coxa' contiguous.. Antenna' ten-jointed, eyes oval, coarsely granu- 

 lated. Head suddenly constricted behind. Tibial spurs very small, tarsi pubescent. 



DACODERUS, Lee. 

 Dacoderus, Lee., Proc. Acad. 1838, 71. 



D. striaticeps, Lee, Proc. Acad. 1858 74; Thomson. Arcana, 1. pi. XII. fig. G. 



A single genus and species constitutes this tribe, remarkable tor the contiguity of the 



