CETONIIN.E 293 



the preceding; anterior tibiae (cf) strongly tridentate, the upper 

 tooth half the size of the second and acute, the hind tarsi almost 

 as long and compressed as in longitarsis, distinctly longer than the 

 tibiae, equal in length to the latter in the female, where the upper 

 tooth is feebler than in the male in the single specimen at hand. 

 Length (cf 9 ) 18.5-21.0 mm.; width 10.5-12.0 mm. Texas. 

 The type example is a female, which is sometimes smaller than 



the male. Three examples seriella n. subsp. 



10 Body small in size, oblong-suboval, opaque and deep velvety-black 

 throughout above, the under surface and legs shining, black; head 

 shining, deeply concave, all the margins strongly elevated, the median 

 ridge narrow and sharp, the concavity sparsely punctate, the up- 

 turned clypeal apex broadly lobed; prothorax moderate, scarcely 

 more than three-fourths as wide as the elytra, widest at base, the 

 moderately beaded sides broadly angulate at the middle; epimera 

 strongly punctured throughout and with very coarse hair; elytra a 

 fourth longer than wide, the sides to beyond the middle parallel, 

 then broadly arcuate to the broadly rounded external angles, the 

 sinus behind the humeri very long; marginal bead very fine and 

 abrupt as usual; raised discal lines obsolete, the surface punctureless; 

 pygidium shining, black, with feeble violaceous lustre, having trans- 

 verse interlacing strigilation, rather well separated but becoming fine 

 apically, the hairs sparse and very short but coarse; anterior tibiae 

 distinctly tridentate. Length (9) 15.5 mm.; width 9.2 mm. 

 Arizona (San Bernardino Ranch, Cochise Co.), F. H. Snow. 

 [Gymnetis impius Fall] impia Fall 



This genus is, as it were, in a state of unstable equilibrium, so 

 far as definite taxonomic units are concerned, and large series, 

 carefully collected in various recorded localities, will be necessary 

 before even an approximate solution of the question can be attained. 

 It might be thought that the anterior tibiae could be employed 

 advantageously at least in separating the sexes, but, although 

 generally stouter and more strongly tridentate in the female, I 

 have found examples now assigned to nitida, for example, in which 

 they are bidentate in what ought to be the female because of the 

 short hind tarsi and more abbreviated outline of the body, and in 

 a female specimen of subcastanea Bates, before me, the right fore 

 tibia has no evident external tooth except the apical, while the left 

 is very distinctly tridentate. The hind tarsi are frequently very 

 stout and compressed, especially in species allied to the true 

 mutabilis, which is a uniformly opaque olive-green species, without 

 trace of pale elytral margination, confined to southern Mexico 

 and Central America and not at all resembling species of the 

 sobrina and obliqua types, extending north of our Mexican boundary 



