50 Mr. Gr. C. Champion's Revision of the Mexican 



the tip ; ninth segment subtrilobate at the apex and deeply excavate 

 anteriorly on each side of the convex central portion, two stout 

 hooks projecting from the internal sac (fig. 17). 



Hab. Mexico, San Luis Potosi, Durango, Guanajuato, 

 Michoacan, Puebla, Guerrero, and Mexico City. 



Gorham correctly surmised that his D. triste, which is 

 an abundant insect on the highlands of Mexico, was not 

 specifically distinct from D. melancholicum (from Guana- 

 juato and Michoacan), the latter simply having the lighter- 

 coloured portions of the prothorax obscurely rufescent or 

 wanting, the characteristic cruciform black patch on the 

 disc being, however, clearly visible in the example marked 

 " type." The specimens quoted by him under D. triste 

 from all the localities south of Mexico belong to other 

 species, as well as the one from Parada, Oaxaca, placed 

 under D. melancholicum. Fresh examples of the male 

 have the antennae densely setulose as in D. nigropilosum. 

 Five specimens of this sex have been dissected, showing 

 the peculiar shape of the ninth ventral segment. A 

 long series of the form described as D. triste has been 

 received from the neighbourhood of the city of Mexico ; 

 the typical D. melancholicum, with darker prothorax, is 

 apparently rare. SchaeiTer (Journ. N. York Ent. Soc. 

 xvi, p. 61) incorrectly refers this species to Polemius. 



40. Discodon atronitens, n. sp. 



Rather broad, shining, finely pubescent; black, the sides of the 

 head in front, the base of the mandibles, the anterior and lateral 

 margins of the prothorax, and sometimes the explanate margins 

 of the elytra in part, the humeri, and the last two ventral segments 

 (in both (J and $), flavescent or reddish. Head rather broad, the 

 eyes somewhat prominent in ^ ; antennae short in $, longer in ^, 

 rather stout, subserrate, tapering towards the tip, joint 3 as long 

 as 4. Prothorax transverse, broadly rounded at the apex; the 

 sides subparallel towards the base, deeply, obliquely notched at 

 about the basal third in ^, simply sinuate and narrowly explanate 

 in $, the hind angles rectangular ; the surface uneven, closely, finely 

 punctate, smoother on the disc. Elytra wider than the prothorax, 

 coriaceous, moderately explanate from a little below the base in 

 both sexes. Inner claw of anterior tarsi broadly lobed, and outer 

 claw of the other tarsi deeply cleft, in (^. 



(J. Eighth ventral segment oblong, broadly rounded at the apex, 



