CETONIIN^E 363 



just behind the middle, the apical processes shorter and more 

 slender, the adjoining cavities more gradually shallowing internally 

 than in either of the preceding species, the basal angles as in schaumi; 

 punctures shallow, variolate, close-set, generally tending to unite 

 longitudinally, forming a peculiar rugulosity, coarse and somewhat 

 irregularly confluent toward the sides; surface evenly and feebly 

 convex, not evidently impressed along the middle, the close sculpture 

 extending to the basal margin; scutellum shorter than usual, with 

 feeble areolae, carinulate apically; elytra rather shining, without 

 tomentose spots, fully one-half longer than wide, a fifth wider than the 

 prothorax, subparallel, the humeri rather prominent laterally; surface 

 subeven, not quite flat, rather gradually flexed downward at the sides, 

 with close-set, elongate, posteriorly open areolae, the side lines of 

 which are unusually deeply incised, the punctures of the flanks 

 small, rounded, shallow and rather close; pygidium very convex, 

 with the usual small shallow areolae; legs rather slender, the femora 

 evidently compressed, the tibiae slender and scarcely at all com- 

 pressed, feebly and irregularly but closely punctato-rugulose; hind 

 tarsi slender, not tapering, distinctly compressed, three-fourths as 

 long as the tibiae. Length 10.8-11.4 mm.; width 4.5-4.9 mm, 



Southern California. Two specimens tridens n. sp. 



27 Form moderately slender, somewhat as in westwoodi, the pygidium 

 more coarsely punctate, the tibiae less stout, the front tarsi shorter 

 and the mentum more deeply concave, black, subopaque above and 

 with short, very sparse brownish erect hairs, which become, medially 

 on the pronotum, distinctly squamiform and from two to three times 

 as long as wide; mentum concave, with entire margins; head as in 

 schaumi; prothorax nearly one-half wider than long, widest across the 

 the hind angles, which are not at all retracted, the sides very broadly 

 and just visibly sinuate before them, arcuately narrowed anteriorly, 

 the apex three-fifths as wide as the base; apical angles with the 

 usual attendant cavity, the hind angles right, triangularly smooth 

 above and not defined by an impressed line; surface broadly convex, 

 the median line impressed, the punctures coarse and shallow, dense 

 at the sides, well separated and coarser toward the middle; elytra 

 moderately flattened, rather more so than in westwoodi, the sculp- 

 ture as in that species; pygidium coarsely cribrate; under surface 

 coarsely, moderately closely punctate; tibiae distinctly less broad 

 than in westwoodi; front tarsi short, the intermediate subequal in 

 length to the tibiae, the posterior a little shorter than the tibiae; all 

 the tars-al joints are concavely compressed, more strongly so basally, so 

 that when viewed from above they appear much narrower at base and 

 in a very peculiar manner. Length 12.5-14.0 mm. ; width 5.0-5.8 mm. 

 Arizona (Fort Mojave, on the Colorado River). Three examples, 



quadratus Fall 



There appears to be scarcely any doubt that lecontei, walshi, 

 junior, crenicollis and crassipes of Westwood, are the same as 

 castanece, retractus, squamulosus, knochi and schaumi respectively, 



