4 CALIFORNIA ACADEMY OF SCIENCES. 



teriorly. Elytra equal in length to the pronotum. First joint of the posterior 

 tarsi fully as long as the next two together, Male sexual characters very sim- 

 ple; fifth segment not modified, sixth narrow with a very small triangular 



emargination at the apex (bilobed) Genus Oligopterus.. 



Species 9. 



Head large, distinctly longer and slightly wider than the prothorax, sub- 

 triangular, very minutely punctate; eyes extremely small, round, on the 

 sides before the middle; labrum with two short, or long and slender acute 

 teeth, the edge adjoining them exteriorly being minutely and abruptly sin- 

 uate, and between them narrowly and rather deeply emarginate. Prothorax 

 quadrate or slightly wider than long; sides moderately convergent poster- 

 iorly. Elytra as long as or very slightly longer than the pronotum. First 

 joint of the ]posterior tarsi much shorter than the next two together. Male 

 sexual characters rather simple; fifth segment very slightly modified, sixth 



deeply and evenly sinuate Genus Lithocharis, Group A. 



Species 10 — 13. 



Head variable, as wide as or slightly wider than the prothorax, sides par- 

 allel, punctuation variable; eyes moderate in size; labrum with two small 

 acute triangular teeth, the edge adjoining them exteriorly being minutely 

 sinuate, and between them rather deeply emarginate. Prothorax finely and 

 sparsely punctate with a rather broad median impunctate area; sides parallel 

 or very feebly convergent posteriorly^. Elytra much longer than the prono- 

 tum. First joint of the posterior tarsi generally but slightly longer than the 

 second. Male sexual modification of the fifth segment very complex, the 

 sixth being rather deeply and roundly emarginate. 



Genus Lithocharis, Group B. 

 Prothorax not longer than wide. 



Posterior angles of the head moderately broadly or 

 rather narrowly rounded. 



Head finely and densely punctate Species 14 



Head much more sparsely punctate. 



Sides of pronotum distinctly convergent x)Osteriorly Species 15 



Sides of pronotum parallel or extremely feebly con- 

 vergent posteriorly Species 16 — 19 



Posterior angles of the head very broadly rounded Species 20 



Prothorax distinctly longer tbbn wide Species 21 — 23 



Head rather small, sub-triangular, veiy minutely alutaceous; eyes very 

 large, coarsely granulate; labrum rather large, truncate at apex, rounded and 

 narrowly explanate at the sides, broadly and very feebly sinuate in the mid- 

 dle, and having a single short, very small, acute median tooth which is slightly 

 dorsal. Prothorax scarcely as long as wide; sides nearly j)arallel. Elytra 

 very slightly longer than wide, distinctly longer than the prothorax. First 

 joint of the posterior tarsi, much shorter than the next two together. Male 

 sexual modification of the fifth segment simple, of the sixth complex. 



Genus Metaxyodonta. 

 Species 24 — 25. 



