4 CALIFORNIA ACADEMY OF SCIENCES. 



teriorly. Elj'tra equal in length to the prouotnm. 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 



emargiuatiou at the apex ( bilobed) Genus Oli^opteruS. 



SpeL;ies 9. 



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

 triangular, very minutely punctate; e^-es 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 pi-onotum. 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- 

 tnm. 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 mwch more sparsely punctate. 



Sides of pronotum distinctly convergent posteriorly Species 15 



Sides of pronotum i)arallel or extremely feebly con- 

 vergent posteriorly Species 10 — 19 



Posterior angles of the head very broadly rounded Species 20 



Prothorax distinctly longer than wide Si)ecies 21 — 23 



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

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

 narrowly explanato 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 parallel. 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. 



Geuus Metaxyodonta. 



Species ^-1 — 25 



