502 niOCEEDINdS OF THE NATIONAL MUSEUM. vol. xxvii, 



and near to the median line are several longitudinal dashes. Vasiform 

 orifice small, tubercled, and subcircular; operculum lieavilychitinized, 

 approximatel}' the same shape and size as the orifice; lingula obscured 

 bv the operculum. On the ventral side the reduced legs can lie made 

 out; antennaj not visible. 



Adult female. — Body so distorted that accurate measurements could 

 not be made; fore-wing, 1.4 by 0.65 mm.; hind tibia, 0.5 mm.; mid- 

 dle tibia, 0.35 mm.; fore tibia, 0.3 mm.; hind and middle tarsi, 0.25 

 mm.; proximal segments, 0.15 mm.; fore tarsus, 0.21 mm. Color, 

 bright yellow, legs and antennse white. Wings immaculate, thickly 

 coated with white wax granules; costal margins golden yellow; main 

 vein of both wings extending to apex; in fore-wing the flexure is 

 at the middle of length, bej^ond it the vein becomes gradually less 

 evident: the basal veinlet arises at base of wing and extends obliquely 

 caudad to margin of wing. Mentum yellow, with proximal segment 

 longest; this is slender and tapers to the middle segment, which is 

 shorter than the others; distal segment gradually tapering to the apex, 

 which is dark brown at extreme tip. E3'es divided into two lobes, of 

 which the anterior lobe is smaller, more transparent, and glowing red; 

 the facets are also much smaller and of a difl^erent shape from those of 

 the posterior one, which is subrectangular in shape and of a dark, 

 reddish-brown color. (See drawing of A. pruinosus.) Genitalia ordi- 

 nary, brown in color and acute conical. 



Adult male. — Fore-wing, 1.23 b}" 0.6 mm.; hind tibia, 0.6 mm.; 

 middle tibia, 0.33 mm.; proximal tibia, 0.3 mm.; tarsi, proximal and 

 middle, 0.21 mm., hind 0.26 mm., the proximal segment of latter 0.15 

 mm. Genitalia ordinar}-. The body very much smaller than that of 

 the female, in other respects essentially the same. 



Coti/pes.—^o. T089, U.S.N.M. 



Collected on Umbellularia calif ornica on campus, Leland Stanford 

 Junior Universit}'; in various places in the Santa Clara Valley; on 

 the lower slopes of the Santa Cruz Mountains, and along the San 

 Ramon Creek at the base of Mount Diablo, Contra Costa County. 

 Also collected on Arhutus onenziesil on King Mountain, on the 

 Ceanothus, near Usal, Mendocino County, July 6, 1901, and on Zhnhel- 

 lularla calif arnica at Redwood Creek, Napa County, June 6, 1901, 

 by Mr. George Coleman. 



The pupa-cases are conmion all the 3"ear. The eggs and young larva 

 were collected from the middle of March to May, and again found in 

 October and November. April 28, 1902, the adults emerged from 

 segregated cases. This species is common in the above localities. 

 Often the leaves are incrusted with the pupa-cases, which are always 

 on the under sides of the leaves. Frequently A. inconspicuus., A. 

 nigrann^ A. quaintancei^ and A. pruinosus are collected from the same 

 leaves with A. errans. 



