TENEBRIONID/E 173 



pressed and elevated, giving the appearance of the true costse of 

 the two preceding genera; this process of transformation from wave- 

 like tumidity to rather acute costuliform ridges may be traced in 

 various stages in different species. The size of the body is greatly 

 diversified, some being among the smallest of the Asidini, while 

 others are of rather more than the average dimensions. The species 

 are rather numerous but rare individually as a rule. Although there 

 is a certain peculiarity of facies common to all of them, even more 

 pronounced in fact than is observable among the various groups of 

 Euschides, there is nevertheless such variety that it becomes neces- 

 sary to define a considerable number of subgeneric groups as fol- 

 lows : 

 Elytra not margined; base of the prothorax rectilinearly truncate or very 



feebly arcuate medially 2 



Elytra margined, the margin never cariniform though more or less 



acute or costiform 3 



2 Body and legs clothed with long fine erect hairs, the tarsi beneath 

 with shorter stiffer and more fulvous hairs; reflexed sides of the 



prothorax not attaining the basal angles Group I 



Body and legs hispid with short erect or suberect hairs, the tarsi beneath 

 with very short spinuliform and more or less fulvous hairs; reflexed 

 margins of the prothorax attaining and forming the basal angles; 



body small in size Group II 



3 Base of the prothorax transverse, strongly bidentate medially; re- 

 flexed margins of the prothorax attaining and forming the basal 

 angles as in all the following groups; elytra as in the preceding groups, 

 not costate; body larger, very stout, sparsely clothed with long erect 

 hairs, the legs with short hairs, the tarsi beneath with dense stiff 



fulvous hairs Group III 



Base of the prothorax truncate, not modified medially. Elytra each 

 with three costee, the outer joining the margin near the base; body 

 convex, rather inconspicuously pubescent, the hairs short, the tarsi 



with short dark spinuliform hairs beneath Group IV 



Base of the prothorax broadly and strongly arcuate. Elytra each with 

 three ridges, the inner feeble, the outer joining the margin near the 

 base; body somewhat depressed, the pale vestiture moderate but 

 coarse, erect and hispid, short, inclined and fulvous on the legs and 

 tarsi, a little longer and dense beneath on the latter somewhat as 

 in Groups I and III Group V 



These groups are in general rather local, although the third, 

 represented by the Mexican villosa, is widely diffused from Texas 

 and southern Mexico to Lower California and the second, repre- 

 sented by acerba, also occupies a large Sonoran region. It is probable 

 that the Mexican Stenomorpha subpilosa Sol., and Asida pubescens 



