THE CANADIAN ENTOMOLOGIST 335 



collection. As late as September 5th mature nymphs could be 

 found here. 



Ephemerella lutulenta sp. nov. 

 Male imago: 



Measurements — Body 8-9 mm. ; Wing 10 mm. ; sctee 12-14 mm. ; 

 fore leg 8 mm. Face dark brown; a spotted reddish-gray streak 

 down carina, and two similar lateral streaks from it to the bases of 

 antennae. Thorax dark reddish brown. Abdomen blackish brown; 

 segments 9 and 10 slightly lighter in colour; venter pale; posterior 

 lateral margins of 9th segment produced into spines. Forceps pale, 

 with tips brown. Setae reddish brown toward bases, but becoming 

 pale toward tips; articulations brown. Legs greenish >ellow, claws 

 brown. Segments of fore tarsi in order of increasing lengths, 1. 5, 

 4, 3, 2; 1 very small; fore femur about five-sixths length of fore 

 tibia. Wings entirely clear. 



Female imago: 



Measurements — Body 9-10 mm.; wing 10 mm.; setae 10-12 

 mm.; fore leg 5 mm. Quite similar to male. Posterior lateral pro- 

 jection of 9th abdominal segment not as long as in male. 



Nymph: 



Measurements — Body 10-11 mm. ; setae 6-7 mm. A large species, 

 with colour varying from a dirty brown to a deep blackish brown, 

 often of a granular appearance. Body and legs hairy. Head with 

 a pair of occipital tubercles of varying size; in the male these are 

 often obscured by the developing eyes of the imago. Pronotum 

 rectangular. Abdom.inal segmxnts 2-9 produced laterally into 

 flat spines; none on segment 1, minute on 2, increasing in size to 

 the 9th, none on the 10th. A double row of spines on dorsal sur- 

 face, very minute on segments 8-10, large on 1-7. On venter, six 

 small black dots on each segment, sometim.cs very faint. Rudi- 

 mentary gills on scgmxnt 1; gills on segments 4-7, covered by a 

 large jointed clytroid gill cover 1.5 mm. in length. Femora stout, 

 brown in colour, with numerous round white dots and several 

 irregular light areas. Tibiae with mxdian brown band, distal ends 

 light, proxim.al ends dark. Tarsi about same length as tibiae, and 

 with proximal half dark and distal half light. Claw with numerous 



