Horn.] lUO [Feb. 21, 



Black, sub-opaque. Head between the eyes rugous, occiput with 

 coarse punctures. Thorax as wide as the head, sub-pentagonal, sides 

 moderately prominent, disc convex, surface transversely wrinkled and 

 coarsely punctured. Elytra broader at base than head or thorax, parallel 

 surface finely scabrous. Body beneath and legs black, feebly shining. 

 Length .70 inch ; 18 mm. 



Male. Antennae with joints 5-3-7 decidedly thickened. Fifth abdomi- 

 nal segment truncate, sixth broadly emarginate lateral processes mam- 

 miliform moderately prominent. Last dorsal segment rotundato-trun- 

 cate. 



Female. Antennae as in cyanipennis. Fifth ventral truncate, sixth 

 oval slightly emarginate at tip. 



Spurs of hind tibiae as in cyanipennis. 



In color resembles Childii, but allied by form of thorax to the preceding 

 species. Its sexual characters res#mble those of the melmna but the two 

 species differ in the form of the last dorsal segment of the male as well as 

 in the form of the thorax. 



The species occurs in California. 



0. Childii, Lee. Pacif. R. R. Rep. p. 52. 



Black, feebly shining. Head sparsely punctured. Thorax sub-quad- 

 rate, somewhat longer than wide, slightly narrowed at base, sides in 

 front arcuate, surface sparsely punctured. Elytra parallel, very finely 

 scabrous. Body beneath and legs black, moderately shining. Length 

 .60-. 70 inch; 15-18 mm. 



Male. Antennae as in cyanipennis. Fifth ventral segment broadly 

 notched at middle, sixth prolonged and deeply cleft, last dorsal truncate. 



Female. Antennae as in cyanipennis. Fifth ventral truncate, sixth 

 acutely notched. 



Inner spurs of hind tibiae slender, acute, outer cylindrical obliquely 

 truncate and concave at apex. 



Occurs in the Sacramento Valley, California. 



0. tenebrosa, Lee. Ann. Lye. V, p. 160 ; Proc. Acad. 1853, p. 333. 



Black, sub-opaque, form moderately robust. Head opaque, finely 

 rugulose, coarsely but sparsely punctured. Thorax opaque sparsely 

 punctured, more densely near the sides, broader than long, sides strongly 

 arcuate in front, slightly narrowed to base. Elytra finely scabrous, less 

 opaque than the thorax. Body beneath and legs black, moderately shin- 

 ing. Length .70-.80 inch ; 19-20 mm. 



Male. Unknown. 



Female. Fifth ventral segment broadly rounded, sixth oval very slightly 

 emarginate at tip. 



Spurs of hind tibiae both acute, the outer broader. 



Not having seen the male either of this species or the next it is impos- 

 sible to say with certainty that they should be referred to the present 

 group. Their affinities, however, appear to be here rather than in the 

 following group. 



Occurs in the region of San Diego, California. 



