268 CTRTON. 



Eyes lateral, situated at the base of the head, large ; in form glo- 

 bose and oval. 



Head transverse, depressed at right angles to the plane of the 

 elytra, short, hardly produced in front ; between the eyes the sur- 

 face is generally foveolate ; the surface is smooth, glabrous, and im- 

 pubescent. 



Thorax considerably broader than the head, broadly transverse, in 

 front slightly emarginate ; the anterior angles are considerably de- 

 pressed and rounded ; the sides are marginate ; the basal line is 

 arcuate, that is, almost parallel to the anterior margin ; the surface 

 is equate, smooth, impunctate, and impubescent. 



Scutellum large, triangular, impunctate, situated in the same plane 

 as the elytra. 



Elytra robust, subcircular, distinctly broader than the thorax, short, 

 and depressed ; throughout the surface are arranged rows of spots in 

 the form of striae ; these spots are more obsolete as they approach 

 the apex ; the surface is smooth, equate, and glabrous. 



Legs : the anterior femora tolerably robust, constricted towards 

 the base, cylindrical. The tibice are short, constricted at their im- 

 mediate base, and slightly thickened towards the apex. The tarsi are 

 short ; the first and second joints are transverse and triangular (the 

 second being somewhat more minute than the first) ; the third joint 

 is broader, and in form subcircular and slightly bilobed ; the apical 

 claw is bifid, at the base robust, and at its inner surface subsinuate, but 

 unarmed by any inferior tooth. The posterior femora (when viewed 

 transversely) are very broadly incrassated, in form ovate, and more 

 broadly, globose (less constricted) laterally than in the preceding 

 genera ; the apex extends nearly to the apex of the elytra. The tibice 

 (Tab. IX. fig. 5g) are robust, with a tendency to being incurved 

 throughout their whole length ; when viewed from behind, the pos- 

 terior surface is longitudinally flattened and grooved, especially to- 

 wards the apex, where it forms itself into a distinct socket for the 

 insertion of the tarsus ; the margination of this groove is straight, 

 hardly subsinuate, produced at the upper part of the socket into a 

 broad angle ; the extreme apex (immediately below the insertion of 

 the tarsus) is terminated by two robust and incurved spurs. The 

 tarsus is short and attenuate, the third joint being shorter, and not 

 broader, than the first and second joints ; the globular inflation of the 

 terminal joint conceals completely from above the apical claw. 



This genus is remarkable for, and may be easily distinguished by, 

 its broadly ovate and depressed form : its glabrous surface at once 

 separates it from Imatium ; it is less parallel, broader, and more ovate 

 than the genus Lithonoma ; while from both (as well as from the 



