DYNASTIN.E 229 



Anoplognatho Rivers. 

 Aphonides Riv. 



This is the most aberrant genus discovered thus far among the 

 American Pentodontids, not only in the mouth parts and sexual 

 differences in the pygidium, but in its Q-jointed antennae, with a 

 subglobular club, having its basal joint large and the outer two 

 not attached at its base but successively beyond, the third joint 

 not half as large as the first, its general structure being exactly as 

 in the European Pentodon. In external features the head is very 

 much as in Ligyrus or Aphonus, and has a high transverse frontal 

 ridge and trapezoidal clypeus, with the apex obtusely acuminate, 

 somewhat as in Anastrategus , with one section of which the peculiar 

 antennae also harmonize, but the mandibles are distinct and strong, 

 attached near the sides of the base of the mentum, enlarged apically, 

 ciliate on the outer side except apically, where they are expanded, 

 widely visible from above, with the outer contour broadly rounded 

 or subtruncate. The mentum is moderately acuminate and 

 deflexed at apex and is coarsely, densely punctate and setose through- 

 out. The last palpal joint is also aberrant, being almost perfectly 

 cylindric, with very obtuse apex. There is nothing remarkable 

 about the body in general, the sterna being moderately pubescent, 

 the post-coxal process of the prosternum small and concealed in a 

 dense brush of long stiff hairs as in Ligyrus and the abdomen with 

 the usual single series of punctures on each segment, the pronotum 

 completely unmodified on the disk in either sex, the legs rather 

 slender, of a purely Ligyrid type, the anterior tibiae tridentate in 

 both sexes; but the moderately flaring apex of the posterior tibiae 

 is coarsely and irregularly crenulate as in Xyloryctes, and the 

 pygidium of the male is very convex, extremely large and with 

 very even surface, while that of the female is of ordinary dimensions, 

 transverse and strongly, transversely swollen near the middle, very 

 much as in Anastrategus which follows. The female otherwise does 

 not differ greatly from the male, except that the body is very much 

 smaller in size. The basal joint of the hind tarsi is much less pro- 

 longed externally at apex than in any of the preceding genera, 

 again approaching Anastrategus. In many ways Anoplognatho 

 serves in fact as an intermediate between the Ligyrid or Aphonid 

 types and Anastrategus, notwithstanding that the pronotum is 



