30 PEOCEEDINGS OF THE NATIONAL MUSEUM vol. 79 



dark, occasionally with paler margin. Elj^ra densely and rather 

 coarsely and rugosely punctate and covered with moderately dense 

 pubescence, entirely blue or green except for pale margin. Body 

 beneath pale with metasternum and abdomen except for tip of last 

 ventral segment dark shining green, legs with outer edge also dark- 

 ened. Length, 5 mm. to 8 mm. ; width, 2 mm. to 3.6 mm. 



Type locality. — California. 



Distribution. — California (Searsville Lake, near Stanford Univer- 

 sity; Marin County). 



Food plants. — Baccharis pilulaim De Candolle, also in small num- 

 bers on near-by Enodictyon (D. H. Blake). 



Remarks. — The pubescence on the elytra and the smaller, less 

 metallic spots on the pronotum separate this species from labrata. 

 The aedeagus, too, is quite distinct from the long tapering one of 

 lahrata. There is apparently no vittate form. One can not be 

 entirely certain whether this or labrata is the true -flavolimbata of 

 Mannerheim, since the description fits either, and the type locality 

 is only " California." T. labrata is recorded only from Monterey 

 and Guadalupe, and since the headquarters of the expedition on 

 which fjavolhiibata was collected were at San Francisco, in which 

 region this species is known to occur, it is more probable that this 

 species is the true flavolirribata of Mannerheim. 



20. TRIRHABDA NIGROHUMERALIS Schaeffer 



Plate 2, Figure 20 



Trirrhabcla nigrohumeralis Schaeffer, Brooklyn lust. Mus. Sci. Bull., vol. 1, 

 p. 170, 1905. 



Descnption. — Small, elongate, somewhat more oval than usual in 

 Trirhabda^ dull pale brown with small occipital and pronotal spots 

 and darkened humeri. Head moderately coarsely, shallowly, and 

 densely punctate, with light pubescence; occipital spot usually small 

 and oblong. Antennae with third and fifth joints subequal. Pro- 

 thorax about twice as wide as long, with sides slightly arcuate, not 

 at all angulate; surface alutaceous, somewhat pubescent, with scat- 

 tered coarse punctures; spots small and black. Scutellum dark with 

 pale tip. El3^ra densely, not coarsely punctate, with short fine 

 pubescence; pale brown with only the humeri darkened. Body 

 beneath entirely pale. Length, 5 mm. to 7 mm.; width, 2 mm. 

 to 3 mm. 



Type locality. — Palmerlee, Cochise County, Ariz. 



Distnbution. — Arizona (Huachuca Mountains, Santa Kita Moun- 

 tains, Prescott, Ashfork, Palmerlee, Bright Angel, Oracle) ; New 

 Mexico (Las Vegas, Jemez Mountains). 



Food plant. — Brickellia sp. (E. A. Schwarz). 



