142 THOMAS SAY FOUNDATION 



heavy coarse brown, crowded next the yellow middle 

 band, openly spaced towards the sides. There is an ob- 

 scure pale double spot at the extreme front of the meso- 

 notum and the remainder of the thorax above is blackish. 

 Legs translucent brownish without pattern. Wings ful- 

 vous tinted with brown veins. Abdomen rather uniform 

 brown in the male, paler and showing diffuse paired spots 

 at sides of terminal segments in the female. Tails yel- 

 lowish brown, clad within with short soft pubescence, and 

 furnished at the tip of each segment with a long infero- 

 internal bristle. 



Male. Segments normal to the 9th save for a slight 

 crescentric callosity (suggestion of a lobe) on the hind 

 ventral apical border of the 8th. The 9th segment pro- 

 longed rearward beneath into a narrowed and upturned 

 subgenital scoop, that nearly doubles the length of the 

 segment and that is upturned at its tip to half the height 

 of the segment. Segment 10 yellowish, enclosed in 9, and 

 soft beneath, entire on its dorsal apical margin ; two short 

 blackish upturned subanal genital hooks rest close against 

 its margin. 



Female. Subgenital plate long covering fully half of 

 the 9th sternite, semicircular in outline of its fore por- 

 tion, well set off by lateral folds from the remainder of the 

 8th sternite. It bears two pairs of small and obscure 

 brownish spots and there are larger spots at sides of seg- 

 ments 8 and 9. 



Distribution. — Western North America: 

 British Columbia, Lake Lakelse, November, 1923. 

 Colorado, Tolland (G. S. Dodds) ; Florissant, June, 1907 



(S. Rohwer) . 

 Washington, Olympia, May 1, 1898; May 20, 1899; June 



2, 1898. 

 Montana, Big Blackfoot River, Potomac, June 20, 1906. 

 ( >regon, Corvallis, April 6 (J. C. Bridwell). 

 Alberta, Maligne Lake, July 1-3; Waterton Lakes, July 

 23, August 8 (J. McDunnough). 



Clioperla marmorata, new species. 



(Plate 13, fig. (i; plate 25, fig. 11.) 



Length to wing tips, female, 18 mm. ; expanse, 28 mm. 



Color yellow, marbled with brown. Head yellow with 

 a blackish band across the frons between the antennae, 

 extended rearward in two blackish triangular lobes to 

 cover the rear ocelli (thus making the yellow of the rear 

 of the head trilobed anteriorly) ; a wash of paler brown 



