RUTELIN.E 69 



coloration but, as a remarkable exception, lugubris Lee. is deep 

 black throughout the body and legs. The clypeus is parabolic, 

 more or less truncate at apex, the labrum short, deeply impressed 

 medially, the ligula very short and the moderate quadrate mentum 

 more or less impressed or declivous anteriorly; the post-coxal 

 process of the prosternum is well developed and the flat intermeso- 

 coxal surface is rather wide and somewhat .anteriorly projecting, 

 though obtuse, and the meso-metasternal suture is usually evident, 

 though always feeble. The pygidium is sometimes almost entirely 

 covered by the elytra and the last spiracle is in or just below the 

 dorso-ventral suture as it is in Phisiotis; it is very large and con- 

 spicuous and the part of the suture between the spiracle and the 

 base is obliterated. The lateral margin of the elytra is often 

 much thickened basally in the female. The South American 

 Odontognathus is closely allied to Pelidnota, but the ligula is more 

 on the same plane as the mentum and is similar in its bright metallic 

 lustre; in Pelidnota the ligula is not so evenly continuous in plane 

 and is frequently blacker or without metallic lustre. In the follow- 

 ing table a few Mexican species, believed to be undescribed, are 

 included. There are three rather well defined subgeneric groups 

 as follows: 



Glypeus entire 2 



Clypeus emarginate and prominently bidentate 3 



2 Head smaller, never notably more than half as wide as the prothorax; 

 body more convex, the elytra not spinose at the apical angles, though 

 generally minutely denticulate; coloration generally non-metallic. 



[Type P. punctata L.] Group I 



Head large, always much more than half as wide as the prothorax; body 

 much less convex and more oval, the elytra always spinulose at 

 apex; colors more metallic. [Type P. strigosa Cast.]. ... Group II 

 3 Body smaller in size, with thicker integument and more strongly 

 metallic coloration. South American, but one species recorded from 

 north of the Isthmus of Panama. [Type P. belli Sharp]. .Group III 



The species of these groups, when segregated, are visibly different 

 in habitus and undoubtedly constitute valid subgenera, and a 

 fuller knowledge of all the known species would probably reveal 

 several others besides. 



