548 SUPPLEMENT. 
ISCHYOMIUS (p. 258). 
This genus, for which I have proposed the group Ischyomiides, as already noted 
(Col. iv. pt. 2, p. 15), would be better placed in the Melandryide. 
OXIDATES (p. 263). 
Oxidates princeps (p. 265). 
To the Mexican locality given, add :—Jalapa (Hoge). 
Four specimens, including both sexes. 
8. Oxidates gibbus, (Tab. XXIII. fig. 10.) 
Short, black, slightly shining. Head very finely, rather sparsely punctate, coarsely and confiuently so between 
the eyes ; antennz comparatively short, extending very little beyond the base of the prothorax, thickened 
towards the apex, the apical joint very stout, oval; prothorax transversely convex, short, more than one- 
half broader than long, about equal in width at the base and apex, the sides with a very prominent, 
reflexed marginal carina, broadly rounded anteriorly, and abruptly constricted immediately before the 
hase, the base very deeply grooved within, the hind angles obtusely rectangular, the surface very finely, 
somewhat closely punctate; elytra strongly gibbous, short, abruptly declivous from the middle, with 
irregular rows of exceedingly large and deep, partly confluent impressions ; beneath shining, almost 
smooth; prosternum deeply excavate along the middle, slightly declivous and strongly produced behind, 
the apex convexly raised ; mesosternum feebly excavate in front; legs black. 
Length 6, breadth 33 millim. 
Hab. Mexico, Misantla (Fohr). 
One specimen. Smaller and shorter than any of the other known members of the 
genus ; the thorax strongly transverse and with the sides very sharply margined; the 
antennz comparatively short; the elytra with exceedingly large and deep, partly con- 
fluent excavations; the prosternal process convexly raised at the apex. 
9. Oxidates elongatus. 
S. Elongate, dull black. Head smooth; antennew elongate, slender, the third joint longer than the fourth ; 
prothorax transversely convex, a little broader than long, the sides rounded anteriorly and slightly con- 
verging behind, the lateral carina not prominent and (except towards the apex) scarcely visible from 
above, the hind angles obtusely rectangular, the base towards the sides deeply transversely grooved 
within and with a shallow marginal groove, the surface smooth towards the sides, the middle of the disc 
exceedingly minutely, closely punctate ; elytra oval, more than twice as long as the prothorax, trans- 
versely convex, abruptly declivous behind, with rows of moderately coarse, distantly placed, foveate 
impressions, which become deeper towards the sides behind, the interstices smooth; beneath smooth, 
shining ; prosternum deeply suleate on either side between the coxe, abruptly declivous and produced 
behind, the apex strongly raised ; first ventral segment deeply transversely depressed in the middle at the 
base ; the tibie bowed inwards and slightly sinuous, the hind pair strongly so, the latter with about the 
apical fourth densely pubescent within. 
Length 164, breadth 74 millim. 
Hab. Mexico, Mochitlan in Guerrero (Baron). 
One specimen. ‘This species connects Mitys with Oxidates, the present insect having 
