H. C. FALL 439 



male; prothorax iiioiv fint4y and less closely puneTate; front claws of male 

 even more strongly enlarged. 



Lr/;(///j 3.5 to 4 mm.; width 1.8to2.1 mm. 



Dhtributioji. — Calif ornui: Independence, June (Fenyes), type female. 

 Arizortf!: Ash Fork, June 18 (Barber ct Schwarz), one male. 



The type is in great part black, the black frontal marks heavy, 

 the prothorax with a very narrow apical margin, broader nearly 

 smooth side margins, a short thin anterior median line and two 

 small basal spots, yellow; elj'tra with basal margin, subhumeral 

 lobes, lateral spots and a few discal flecks, yellow. In the Ari- 

 zona male the yellow markings are larger and the upper surface 

 might best be described as yellow, with the pronotal M heavy, 

 the elytra with standard spots, those of the inner series irregular 

 and subconfluent, legs more yellow than black. In both sexes 

 the pygidium has two confluent apical yellow spots, and the last 

 ventral is largely yellow. In caliform'cus the last ventral 

 is entirely black and the p3'gidium only rareh' shows two small 

 widely isolated ^^ellow spots. In the female type the elytral 

 shield is represented by a small yellow dot ; in the Arizona male it 

 is nmch larger and quite conspicuous. 



120. Pachybrachys tridens Melsheimer 



Pale yellow with broad sharply limited black markings; anten- 

 nae usually, and legs entirely yellow, size small, lustre dull. Eyes 

 separated by about twice the length of the basal antennal joint 

 in the male, and by two and one-half to three times the length 

 of this joint in the female; ocular lines fine; front claws of male 

 not enlarged. Ave. length 2.7 mm. Eastern half of United 

 States. 



Head nearly uniformly, not densely punctured, frontal spots usually very 

 much reduced or almost entirely wanting in the male, better developed or even 

 broadly suffused in the female. 



Prothorax strongly transverse, slightly narrowed in front with the sides 

 feebly arched in the male, more obviously narrowed and with the sides more 

 rounded in the female; yellow with a subquadrate black spot each side nearer 

 the base than the apex, and a median stripe dilated in front and usually divided 

 anteriorly by a yellow line, the median and lateral marks very rarely con- 

 nected in front; punctuation rather sparse and somewhat irregular. 



Elytral striae lightly impressed laterally, scarcelj' so on the disk, fairlj^ regu- 

 lar; shield moderate, feebly or scarcely elevated, yellow. The elytra may be 

 described as yellow with a transverse black basal fascia wider at the sutin-e, 

 along which it narrowly joins a still wider posterior fascia. The anterior 



TRANS. AM. ENT. SOC, XLI. 



