( lol ) 



Ibretiliiix and -tarsus ])roloiigecl ; first segment of midtarsns with comb, but only 

 the most proximal bristles long ; first segment of hindtarsus only as long as 

 the fonr other segments together ; long apical sjiur of hindtibia half the length 

 of the first tarsal segment. Paronychium reduced, with short lobe. 



i. Tenth abdominal tergite elongate, sharply })ointed, convex above 

 (PI. XXVIII. f. 10, dorsal view), abruptly curved downward, forming a long 

 liook (PI. XXVIII. f. II, side-view) ; stcrnite with a very broad lobe (PI. XXVIII. 

 f. Id), which is very feebly sinuate. Clasper comparatively shorter and more 

 rounded, especially dorsally, than in cliersis; harpe somewhat similar to that 

 of clicrsis, but the ventral lobe very short, and the long process more oblique 

 and somewhat undulate (PI. XXXVIII. f. 8). Penis-sheath (PI. XXIX. f. 4) 

 with a rather short, blunt process which is concave on the inner side. 



?. Vaginal plate represented by PI. XX. f. 19 in a ventral view, by f. 20 in 

 a side-view; a large subapical cavity, in which the vaginal orifice is situated, partly 

 covered in front by a convex lobe. 



Larva green ; side-bauds white with narrow black anterior border ; horn smooth, 

 black above and below. — Food : Sijmpkoricarpus racemosus. 



Pupa : tongue-case free, rounded, 8 mm. long. 



Two broods. 



There occur, in the same places, two forms difi'ering in the colour of the thorax. 

 These forms are said to be seasonal (Smith, I.e., p. 234). The dated material in the 

 Tring Museum and other collections confirms on the whole Mr. Bruce's positive 

 statement, referred to by Smith, I.e., that of the two broods one is always albescens 

 (with the black thorax) and the other vancouverensis (with the grey thorax). 

 However, some of the specimens of the early brood, or rather of an early date, are 

 as black on the thorax as some of the later individuals, and others are intermediate. 

 This seeming irregularity may be due to the phenomenon known of other Sj/IiiiKjidae 

 that pupae often lie over from one brood to the other, or longer. The black notum 

 is doubtless the younger character, and both broods of the sptcies may be on the 

 way towards developing into a black-backed insect. 



Further researches in this respect are necessary, and we hope that the keen 

 entomologists on the other side of the Atlantic will not be slow in making further 

 careful observations. We here can do no more than merely state that the two 

 forms are connected by intergradations and are identical in structure. 



a. H. vancouceremis f. vancoKcereiisis (PI. XIII. f. ;?, S.) 



S/i/iinx vancuurereiisis Edwards, l.r. (Vancouver, August) ; Smith, I.e. p. 234 (18S8). 

 Sjiliiju' rashti Strecker, l.i'. (1878) (Arizona). 



S ?. Thorax grey. — Tiie spring form from hiliernated pupae? 



//. //. r<(Hrou(i'reii.'<is f. <illicfiC('iis (Pi. XIII. f. 4, S). 



Sphiiu: alhescens Tepper, I.e. (1881) (Colorado); Hanh., Ctinatl. Eiit. x,\ix. p. 292 (1897) (Mani- 

 toba, vii.) ; id.. I.e. .\.\xi. p. 52 (1899) (Manitoba); Heath, Cunad. Eut. xxxii. p. 94 (1900) 

 (Manitoba, vi.). 



S ? . Thorax black. — Tlie summer form ? 



Hab. Pacific Subregion : from California and British Columbia, westward to the 

 cast side of the Rockv Mountains. 



