DYNASTIN.E 255 



shorter, more rapidly and acutely acuminate and but little longer 

 than the head, the apical bilobed carina nearly similar; antennal club 

 but little shorter than the entire stem, though shorter than in satyrus, 

 the joints of the stem much shorter; prothorax throughout nearly 

 as in satyrus, except that the abrupt slope begins only a little before 

 the middle, viewed from above, with the sculpture of the concavity 

 finer and sparser, the punctures along the sides and the dense rugu- 

 osity antero-laterad also nearly similar; elytra as in satyrus but with 

 the striae less coarse and very much more feebly impressed; pygidium 

 shorter, more than three times as wide as long, the punctures 

 similarly distinct and close-set throughout but mingled with very 

 minute punctules. Female not narrower and almost similar in 

 outline to the male, the head nearly as in the female of satyrus; 

 prothorax also nearly as in that species and similarly with very 

 strong entire basal bead; elytra similar, except that they are not 

 evidently wider than the prothorax, the coarse striae and general 

 sculpture very much stronger than in the male; pygidium nearly 

 as in the male but less convex and without evident intermingled 

 punctulation. Length (i cf, 2 9) 22.8-24.5 mm.; width 13.3-13.7 

 mm. Region about Lake Michigan and Lake Superior. 



lacustris n. sp. 



A Similar to lacustris (cf ) but with a shorter prothorax, broader, 

 more posteriorly inflated elytra, on which the sculpture is still 

 feebler and gradually still more obsolescent posteriorly, and with 

 a very slender cephalic horn: the sides of the prothorax are more 

 broadly and evenly arcuate behind the apical obliquity and the 

 base is broadly, feebly arcuate, becoming gradually sinuate sub- 

 laterally, while in lacustris it is simply gradually, moderately and 

 more narrowly lobed medially; pygidium as in lacustris. Length 

 (cf) 24.5 mm.; width 14.5 mm. A single example from an un- 

 recorded locality, but probably from Nebraska. 



tenuicornutus n. subsp. 



3 Last palpal joint securiform, rapidly narrowed toward base on the 

 inside and, at base, only half as wide as at the middle. Body nar- 

 rower and more elongate than in satyrus and rather less convex, 

 deep black, shining, rufo-ferruginous beneath. Male with the head 

 rather more than a third as wide as the prothorax, everywhere 

 coarsely and densely punctato-rugose, the apical carina bilobed, 

 parallel at the sides, the horn short, not very thick at base, acute 

 and only slightly longer than the head, rugosely sculptured except 

 apically; prothorax narrower than in satyrus and with the steep slope 

 beginning but little beyond the middle of the length, viewed ver- 

 tically, its margin slightly protuberant at the middle but evenly 

 rounded, not in the least bilobate, the concavity deeper than in 

 satyrus but otherwise nearly similar; base transverse, barely at all 

 arcuate, the bead thick and very strong throughout; elytra slightly 

 longer than wide, equal in width to the prothorax and three-fourths 

 longer, rounded in apical two-fifths, the sculpture superficial, 

 consisting of scarcely at all impressed and rather fine series of moder- 

 ate, posteriorly open annul!, confused medially on the second 



