232 MEMOIRS ON THE COLEOPTERA 



Anoplognatho, except that they are tridentate externally as in 

 Ligyrus, the middle tooth becoming very large in the cessus type, 

 almost eliminating the two lateral teeth, which become greatly 

 diminished in size. The apex of the clypeus is obtusely acuminate 

 and moderately upturned, the transverse frontal ridge inconspicuous 

 and generally divided. The post-coxal process of the prosternum is 

 moderate and bristles with setse throughout as in Ligyrus, the pro- 

 notum always with a strong marginal bead at base as in Strategus, 

 and the pygidium differs in the sexes, sometimes very distinctly. 

 The propygidium is always transversely though moderately sculp- 

 tured, and stridulation is usually evident. The hind tibiae are as 

 in Strategus, the outer side at tip being deeply sinuate, the bottom 

 of the sinus variously modified. The anterior tibiae are quadri- 

 dentate as in Strategus, and the upper tooth is always feebly de- 

 veloped; the basal joint of the hind tarsi is slender, also as in 

 Strategus, and not produced obliquely at apex as in Orizabus; 

 Anoplognatho is intermediate in this respect. The elytra have each 

 a coarse deep subsutural stria, which is sometimes flexed outwardly 

 at base along the scutellum. 



The species are rather numerous, although only two have been 

 described and they are distributed from the more southern Atlantic 

 coastal regions to northern Mexico. Those in my collection may 

 be known as follows; they are divisible into two distinct groups, 

 inhabiting different zoological regions: 



Antennal club nearly as in Pentodon and Anoplognatho, its joints suc- 

 cessively diminishing in length; mandibles broadly obtuse and lobi- 

 form externally, the lateral teeth feeble or obsolete; body broader, 



more oblong, less convex and less shining. Sonoran regions 2 



Antennal club with its joints of equal or subequal length as in Strategus; 

 mandibles strongly tridentate, though less strongly in the female; 

 body more oval, convex and shining, of more pallid coloration and 



smaller size. Atlantic regions 7 



2 Body larger in size, at least 30 mm. in length 3 



Body very much smaller 6 



3 Elytra gradually and but very feebly inflated behind 4 



Elytra more or less conspicuously inflated behind . . . -. 5 



4 Pygidium (9) with the transverse ridge slightly above the middle, 

 the surface thence to the base rather densely and rugosely punctate 

 and pubescent. Body oblong, broad, rather strongly convex and 

 shining, black, the under surface and legs bright red-brown; sternal 

 vestiture abundant but rather short, erect; head rather more than 

 a third as wide as the prothorax, coarsely, confluently punctate 



