H2 MEMOIRS ON THE COLEOPTERA 



segments, the mentum densely hairy in the former, nude in the 

 latter, sex; legs stout, the middle coxae rather well separated. . . . 16 



n Ligula small, sharply pointed, the palpi projecting from the sides of 

 the point; mentum small, oval, feebly convex, sparsely punctured 

 and clothed with very long erect pubescence; body oblong, stout, 

 moderate in size, convex; clypeus short, with the sides near the 

 sharply reflexed arcuate apex usually sinuate for a short distance; 

 mandibles slender, slightly everted at tip; middle coxae widely 

 separated; sterna conspicuously pubescent; legs moderate, the tarsi 

 slender and rather long. [Type S. nubecnla n. sp.]. Sonoran 

 regions Spilosota n. gen. 



Ligula abruptly much narrower than the mentum, flat or nearly so, 

 truncate to sinuate at tip 12 



Ligula broad, transverse, almost as wide as the mentum 15 



12 Hind tarsi much shorter in the female than in the male as a rule, 

 but always slender and much longer than the tibiae 13 



Hind tarsi very short, generally much shorter than the tibiae in both 

 sexes; body more elongate 14 



13 Body oblong, generally somewhat depressed, pallid, the pronotum 

 usually with two large dark spots, the elytra with oblique lines, 

 sometimes resolved into a few spots, frequently sparsely pubescent; 

 clypeus large, flat, feebly subtrapezoidal, with rounded sides, broadly 

 arcuate, finely and feebly reflexed apex and broadly rounded angles; 

 middle coxae always well separated; posterior edge of the pronotum 

 invariably finely double. [Type Melolontha signata Fabr.] Neo- 

 tropical regions *Cyclocephala Latr. 



Body oblong-oval, more convex, of very uniform pale b'rownish-yellow 

 or flavate coloration, usually immaculate in the subarctic regions 

 but frequently with more or less feeble and transversely sinuous 

 elytral ornanientation in the tropics, the elytra sometimes sparsely 

 pubescent; clypeus shorter, more reflexed at apex, subtrapezoidal 

 to semicircular, more coarsely sculptured than in the preceding but 

 similarly never sinuate; middle coxae only narrowly separated; 

 posterior edge of the pronotum never finely double as in the pre- 

 ceding, always immarginate medially, sometimes with feeble beading 

 laterally. [Type Melolontha immaculata Oliv.] North and South 

 America Ochrosidia n. gen. 



14 Form elongate-oval, convex and shining, pallid and immaculate, the 

 head and prothorax generally darker than the elytra; clypeus smaller, 

 more trapezoidal, still more reflexed at tip and differing from any of 

 the preceding genera in being more or less evidently angulate at each 

 side of the apex, which is more truncate; middle coxae narrowly 

 separated; base of the pronotum generally beaded toward the sides; 

 larger claw of the anterior male tarsi broadly forked or divaricate 

 at tip. [Type Cyclocephala dimidiata Burm.] Sonoran regions of 

 North America Dichromina n. gen. 



Form and general habitus nearly as in the preceding genus throughout but 

 with the hind tarsi not quite so short, the posterior being notably 

 longer than the tibiae in the male, though distinctly shorter than the 

 tibiae in the female, differing principally in the normal, unequally 



