6 INSECUTOR INSCITI^E MENSTRUUS 



of this form was bred and proved to be lazarensis. Last season 

 I took this form to be a variation of decticus, but evidently 

 wrongly. A considerable number of the specimens listed by 

 me under decticus (Ins. Ins. Mens., vii, 18, 1919) will have 

 to be removed. 



In the Yukon watershed, including the lakes at its head and 

 across the White Pass to the end of the Lynn Canal, lazarensis 

 is also the dominant species ; but it has taken on a wholly dif- 

 ferent aspect. The normal form occurs, but it is rare. Usually 

 the mesonotum is light gray without trace of yellow or brown 

 shading. The lines vary from narrow to broad, the broad 

 form the commonest, sometimes completely confluent, leaving 

 only a pair of star-like whitish specks, or even the mesonotum 

 wholly blackish brown. The markings seem to have run wild, 

 all sorts of freakish-looking variations occurring. As a whole 

 a rather distinctly marked race is indicated, for which the 

 name borealis Ludlow is available, although the type of borealis 

 is an almost normally marked lazarensis. 



Total, 3,612 specimens : (normal form) Prince George, Brit- 

 ish Columbia, May 9-20, 22, 25, 1919; Terrace, British Co- 

 lumbia, August 12, 13, 14, 1919 ; Salvus, British Columbia, 

 May 27, 28, June 3-8, 13, 1919 ; Kwinitsa, British Columbia, 

 May 24, 25, 1919; {borealis form) Skagway, Alaska, June 24, 



25, 28, 29, July 28, 1919; Glacier, Alaska, June 26, 1919; 

 Pitchfork Falls, Alaska, July 28, 1919; Atlin, British Colum- 

 bia, July 22-25, 1919 ; Carcross, Yukon Territory, June 21, 



26, 27, 1919; White Horse, Yukon Territory, June 26-29, 

 July 1-5, 7, 8, 16-18, 1919 ; Tahkeena River, Yukon Territory, 

 July 19, 1919; Hootalinqua, Yukon Territory, July 15, 1919; 

 Half way to Big Salmon, July 15, 1919 ; Big Salmon, Yukon 

 Territory, July 15, 1919 ; Byer's Camp, Yukon Territory, July 

 6, 1919 ; Tantalus Mine, Yukon Territory, July 6, 1919 ; Car- 

 mack's, Yukon Territory, July 14, 1919 ; Horse Falls, Yukon 

 Territory, July 13, 1919; Selkirk, Yukon Territory, July 13, 

 1919 ; Dawson, Yukon Territory, July 7-10, 1919. 



Also from Doctor Hewitt's collection. Glacier, British Co- 

 lumbia (normal form), July 28, 1916 (C. G. Hewitt), and 



