THE CANADIAN ENTOMOLOGIST. 335 



average sequence of joints is as follows : Joint 3 longest, 2 and 4 sub- 

 equal, next I, sometimes i and 5 subequal, next 8, joints 6 and 7 shortest, 

 sometimes subequal. Formula: 3 (24) 15867. Joints measure in /x : 

 1-48, 2-60, 3-72, 4-60, 5-44, 6-28-32, 7-28-30, 8-4C. Legs short and 

 stout. Measurements of middle leg in fi : Coxa, 30-35 ; femur with 

 trochanter, 85; tibia, 60 ; tarsus, t,t, ; claw, 12. Digitules club-shaped' 

 extending beyond claws. Hairs and spines of this species are few and 

 are very short and fine. 



Habitat. — AX. San Diego, Cal, on Pluchea sericea. It covers the 

 twigs quite thickly, A Chalcid fly attacks the female when the cottony 

 sac is forming, but does not seem to materially check the scale. 



NEW SPECIES OF PERLID.4i:. 



BY NATHAN BANKS, EAST FALLS CHURCH, VA. 



In looking over my collection preparatory to a rearrangement of the 

 forms, I find several new species, that I describe below. One of them 

 represents an interesting new genus, allied to Nemoura. I have added 

 illustrations of the genital structures, as these are of considerable value in 

 the determination of the species. I hope soon to be able to prepare a 

 revision of our species of this family, one of the most primitive of existing 

 winged insects. 



Acrotietcria puf/ii/a, n. sp. — -Head uniformly yellowish, wnthout 

 marks ; antennae and pronotum duller yellowish ; thorax and abdomen 

 more brownish ; legs yellowish ; setae jDale yellow. Wings hyaline, 

 venation yellowish. The ocelli form a triangle a little shorter than 

 equilateral, posterior ocelli very much closer to each other than to eyes ; 

 ])ronotum narrowed behind, very rugose above on each side, the smooth 

 median space much wider behind than elsewhere. Wings only a little 

 longer than the abdomen ; many cross-veins in apical region, but not in 

 submarginal space ; many costal cross-veins, and five or six beyond the 

 end of subcosta ; six to eight cross-veins in both cubital and median series. 

 Ventral plate of female much more produced than in any described form. 



Length, 17 mm. One female from Three Rivers, California (Baker). 

 It is the smallest species of the genus in our country, but it is probable 

 that other specimens will be larger, as these forms are variable in size, 



October, 1906. 



