46 Mr. C. O. Waterhouse on new Madagascar Coleoptera. 
somewhat flattened on the back, with a fine sutural stria; the 
apex of each elytron with a very slight truncature. 
The sexes are extremely alike. The male, however, is 
rather less robust in build ; the apical joint of the antenne is 
distinctly longer than the preceding ; the apical segment of 
the abdomen has a very slight indication of a notch at the 
apex, with a slight impression ; and the claw-joint of the tarsi 
is very slightly dilated at the apex. 
This species is very close to LZ. simplex, Waterh. (Ann. & 
Mag. Nat. Hist. 1880, v. p. 417). It differs in having the 
head distinctly broader, the eyes more prominent, standing 
out more away from the head posteriorly ; the lateral tubercle 
of the thorax is more prominent, and the legs are pale brown. 
Lamiide. 
DIORISTUS, n. gen. 
Head gently concave between the antennal tubercles, which 
are only very slightly elevated. Antenne as long as the 
whole insect in the male, a little shorter in the female ; densely 
pubescent, with a few longer hairs beneath the third, fourth, 
and fifth joints; the first joint short, thick, and subovate ; 
the third a trifle longer than the first and second together ; 
the fourth a little longer; the fifth to tenth distinctly shorter, 
subequal; the eleventh in the male rather longer than tie 
tenth. Eyes strongly granular, almost divided. Thorax 
subquadrate; the disk flattened, and with a well-marked 
elevation on each side; the sides with a small tubercle rather 
in front of the middle. Scutellum a curvilinear triangle, 
transverse. lytra moderately elongate, not very convex, 
perpendicularly deflexed at the sides, scarcely declivous at the 
apex ; at the base much broader than the thorax, gently nar- 
rowed a little distance below the shoulders, and thence to near 
the apex nearly parallel in the female, slightly narrowed in 
the male; the apex broad and obtuse, but scarcely truncate, 
ciliate. At the base of each elytron (a little nearer the scu- 
tellum than the shoulder) is a well-marked longitudinal 
elevation. Intermediate tibiee not suleate; posterior tibie as 
long as the tarsi. Claws divergent. Prosternal process with 
a well-marked obtuse tubercle. Mesosternal process nearly 
perpendicular in front. 
The species upon which I propose to establish this genus 
calls to mind the group of Xylorhiza ; but all its general cha- 
racters are those of Niphona, from which it differs much in 
appearance, in the elevation on each side of the disk of the 
