314 Transactions South African Philosophical Society, [vol. ml. 

 Key to the Genera. 



A 2 . External edge of coxae completely hidden by the elytra in 



both sexes Myodermides. 



B-. Upper lobe of maxillae very short, spatulatc, sparsely 

 setulose at tip. 



Ligular part, broadly scooped at apex. 



Hind tibiae very little dilated at apex Myoderma. 



Hind tibiae plainly dilated at apex Diploa. 



B\ Upper lobe of maxillae lanceolate and pcnicillate at tip. 



Ligular part bi-lobatc Diploeida. 



A'. External edge of coxae bulging beyond the elytra in the male (Elpidides.) 



Upper lobe of maxillae very short, sub-quadrate. 



Hind femora and tibiae abnormally developed in the male. 



Ligular part of mentum projecting as a small bi-lobate 



process Elpidus. 



Ligular part of mentum truncate at tip, the cavities for the 



insertion of palpi quite apical Xiphoscelidus. 



Gen. MYODERMA, Burm., 

 Handb. d. Entom., iii., 1842, p. 732. 



Mentum longer than broad, narrower at base than at apex and 

 without any traces of a ligular part, deeply and broadly emarginate 

 in the centre and having quite laterally a very broad cavity reaching 

 the outer angle for the insertion of the labial palpi the last joint 

 of which is sub-cylindrical, but tapers slightly towards the apex 

 where it is truncate; maxilla somewhat robust, but laminate 

 inwardly and ending at apex in a rounded process, upper lobe, or 

 galea, reduced to a spatuliform process slightly longer than broad, 

 and pluri-setose at tip ; clypeus parallel, produced in the middle of 

 the anterior part in a short, reflexed lamina more sharply triangular 

 in the 3 than in the 2 ', eyes very large, canthus long, very sharp ; 

 antenna! club not longer than the pedicel in either sex ; prothorax 

 broader than long, ampliate rounded laterally in the middle, 

 bi-sinuate at base with the basal angle sharp; scutellum triangular, 

 sharp at tip; elytra sub-parallel, but plane, costate, mesothoracic 

 epimera narrow but visible from above : pygidium sub-vertical ; 

 mesosternum with a short, blunt process; legs moderately long; 



