214 MEMOIRS ON THE COLEOPTERA 



apex of the clypeus, in front of the carina, is usually minutely 

 mucronate medially. The maxillary galea is slender and appar- 

 ently has two longer terminal teeth and an outer one more retracted 

 and smaller. The head also differs from that of Pseudaphonus in 

 having no such well marked central tubercle, but usually instead, 

 a simple fine feeble ridge adjoining the clypeal suture. The 

 prothorax differs in being widest at base, generally with distinct, or 

 at least never broadly rounded, angles, but with similar immarginate 

 and medially lobed basal margin. The mentum is more narrowly 

 drawn out at apex, the lower beading of the pygidium less developed 

 and the erect post-coxal process of the prosternum slender, obtusely 

 acuminate and setulose throughout. The pygidium does not differ 

 much sexually, except that it is more convex in the male and its 

 lower margin, as well as the apex of the abdomen, is heavily beaded, 

 both beads generally interrupted medially; the apical abdominal 

 beading is never present in Pseudaphonus. Finally, the body is 

 always much smaller in size and the geographic habitat is very 

 different, Aphonus occupying the moist and well watered Atlantic 

 districts, while Pseudaphonus inhabits the arid mountainous 

 country of the southwestern or Sonoran regions. The species are 

 rather numerous but sometimes closely allied among themselves, 

 so far as general habitus is concerned; those in my collection may 

 be known as follows: 



Three prominences of the subapical clypeal carina equal among them- 

 selves 2 



Three prominences very unequal, the median very small and often com- 

 pletely obsolete; body smaller in size and more abbreviated 10 



2 Form elongate, subparallel, the elytra not distinctly inflated, the color 

 black, obscure ferruginous beneath; integuments only moderately 

 shining to dull in lustre 3 



Form stout, the elytra more or less inflated 4 



3 -Body convex; head small, transversely rugulose, it as well as the 

 clypeus coarsely rugose, the rugae bioblique on the latter; subapical 

 teeth rather broadly rounded; prothorax about a third wider than 

 long, the sides moderately converging, evenly and rather strongly 

 arcuate from base to apex, the basal angles from above slightly 

 obtuse, though scarcely more than blunt at apex, rather well defined, 

 the apical rather sharp, the apex circularly sinuate; base immarginate 

 as usual, strongly lobed medially; punctures fine and sparse, stronger 

 laterad and especially strong and close-set toward the apical angles; 

 elytra only very slightly longer than wide, a fifth wider than the 

 prothorax and about three-fourths longer, circularly rounded pos- 



