DYNASTIN^: 189 



Mandibles bidentate at tip; front bituberculate; ligula rather broad, 

 truncate; post-coxal process of the prosternum with its apex large, 

 flattened, having an anterior convex nude, and a posterior explanate 

 ciliate, portion; sterna glabrous; pronotum with an anterior inden- 

 tation and small tubercle; body large in size Group I 



Mandibles tridentate externally; front transversely carinate at the base 

 of the clypeus; ligula narrower, generally bluntly acuminate; post- 

 coxal process smaller, not flattened at tip and bristling throughout 

 with long setse; sterna more or less conspicuously pubescent; body 

 moderate or small in size 2 



2 Pronotum with a small anterior indentation and feeble subapical 

 tubercle 3 



Pronotum without trace of the anterior indentation, the tubercle ob- 

 solete 4 



3 Clypeal teeth small, approximate; body generally short and ovoidal, 

 the head small ; maxillary galea tridentate Group 1 1 



Clypeal teeth widely separated; body elongate-oval, the head rather 

 large; maxillary galea bidentate Group III 



4 Body nearly as in Group II and similarly with the head notably small. 



Group IV 



Groups I, III and IV are wholly tropical, while Group II, the 

 true Ligyrus, is distributed from Canada to and throughout the 

 Sonoran regions of Mexico. 



Group I. 

 Subgenus Grylius nov. 



There are so many and such weighty differences between this 

 group and the last three defined above, that there is more proba- 

 bility of true generic value than the status here suggested for it. 

 The body is of large to moderately large size and the species are com- 

 paratively few in number; those in my collection may be defined as 

 follows: 



Elytral sculpture becoming completely effaced broadly toward the suture. 

 Body stout, convex, shining, oblong-suboval, piceo-rufous in color 

 above, still paler bright brownish-red beneath, glabrous throughout; 

 head moderate, barely two-fifths as wide as the prothorax, rugulose, 

 smooth at base, the eyes very moderate, not at all prominent, the 

 front impressed medially; tubercles separated by a little less than 

 half the distance between the eyes, and at the extreme base of the 

 clypeus as usual; suture transverse, fine but traceable throughout; 

 clypeus trapezoidal, less than twice as wide as long, the sides very 

 feebly sinuate, finely and evenly margined, the upturned teeth very 

 approximate; mentum on the disk flat, smooth and nude, excavated 

 at the base; prothorax one-half wider than long, the sides moderately 

 convergent, very evenly and rather strongly arcuate from the rounded 



