DYNASTIN^E 261 



coarsely toward the sides. Length (cf), from the end of the clypeus, 

 45.0-50.0 mm.; width 23.5-27.6 mm. Arizona grant! Horn 



A form was described recently by Sternberg (Stett. Ent. Zeit., 

 1910, p. 26), from Texas, as a subspecies of tityus under the name 

 corniger; while this is unknown to me, I do not think that it can be 

 a depauperate male of tityus, as the thoracic spicules have there 

 exactly the same relative position as in the normal tityus, while in 

 corniger they seem to differ somewhat in that respect. The female 

 appears to be rather less common than the male in tityus and prob- 

 ably also in granti. Tityus exudes a very strong odor, not particu- 

 larly disagreeable but pervasive, and I am told that the odor from 

 a tree fairly loaded with the beetles, is sometimes carried by the 

 wind for nearly a mile. Granti bears no close relationship to 

 hyllus, the latter being much more closely allied to tityus than 

 it is to granti, except that the thoracic spicules of the male are 

 placed near the base of the horn as in the latter species and are not 

 more remote from the base of the horn as they are in tityus. 



Megasominus n. gen. 



There is but little to add to the short diagnosis given above, 

 other than to state that there is a marked difference in habitus 

 between the Megasoma thersites of LeConte, and the more gigantic 

 elephas, which besides inhabits a very different zoological region; 

 the pubescence is also of a very different kind, being long, sub- 

 decumbent and hair-like and not very short, dense and velvety as 

 in that species; the type may be described as follows: 



Male oblong, convex, black, slightly shining, the under surface and legs 

 also black or blackish; pubescence pale yellowish-gray, dense, very 

 sparse or wanting on the medial and antero-laterad parts of the pro- 

 notum, and on the head except behind the horn, dense and still 

 longer on the under surface, but less dense and more irregular on 

 the abdomen and under surfaces of the femora; head two-fifths as 

 wide as the prothorax, with prominent, posteriorly plectrate eye- 

 canthus, the eyes very moderate, not at all prominent; punctures 

 fine, rather close, the surface shining; clypeus short, feebly trape- 

 zoidal, with the sides feebly arcuate, much thicker vertically toward 

 apex than basally, the apex broadly sinuate, the erect tubercle at each 

 angle strong, the transverse elevated line near the apex distinct; 

 labrum with a dense yellow fringe throughout the width; horn twice 

 as long as the head, erect, strongly, evenly arcuate backward, its 

 apex gradually wider and strongly, slenderly bifurcate; from the 



