122 MARINE AND FISHERIES 



5 GEORGE v., A. 1915 



lateral streaks from it to the base of antennae. Thorax dark reddish brown. 

 Abdomen blackish brown; segments 9 and 10 slightly lighter in colour. Venter 

 pale. Posterolateral margin of 9th segment produced into spines. Forceps 

 pale with tips brown. Setae reddish brown towards base but becoming pale" 

 toward tip; joinings brown. Legs greenish yellow, ungues brown. Segments 

 of fore tarsi in order of increasing lengths 1, 5, 4, 3, 2; 1 very small; fore femur 

 about 5/6 length of fore tibia. Wings entirely clear. 



Female imago: 



Measm-ements : Body 9-10 mm.; wings 10; setse 10-12; fore-leg 5. 



Quite similar to male. Posterolateral projection of 9th abdominal segment 

 not as long as in male. Ninth segment ventrally produced posteriorly into a 

 truncated triangular plate, with end emarginate. 



Nymph: 



Measurements: Body 10-11 mm.; setae 6-7. 



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 sometimes obscured by the 

 developing eyes of the imago. Pronotum rectang-ular. Abdominal segments 

 2-9 produced laterally into flat spines; none on segment 1, minute on 2, increasing 

 in size to the 9th; none on segment 10. A double row of spines on dorsal surface, 

 very minute on segment 8-10, large on 1-7. On venter 6 small black dots on each 

 segment, sometimes very faint. Rudimentary gills on segment 1 ; gill on segments 

 4-7; a large jointed elytroid gill cover 1 ^S mm. in length. Femora stout, brown in 

 colour with numerous round white dots and several irregular light areas. Tibiae 

 with median brown band, distal ends light, proximal ends dark. Tarsi about 

 same length as tibiae and with proximal half dark and distal half light. Claw 

 with numerous pectinations. Setae well fringed with hairs along middle, almost 

 bare at base and tip. Each 2 alternate segments brown. 



The nymphs were taken almost everywhere about Go Home Bay from May 

 29th to June 19th. Mr. R. P. Wodehouse has also given me specimens from 

 various places around Georgian Bay including Shawanaga Bay, Pentecost Island, 

 French River, Sturgeon Bay. 



Ephemerella lineata Clemens.* 



„ 7 • (PI- XIII, Fig. 5). 



Female imago: 



Measurements: Body 9 mm.; setse 14; wing 10-5 mm. 



Very similar to female of E. lutulenta but has a distinct rusty brown median 

 longitudinal stripe on dorsal surface of abdomen. In a fresh specimen the stripe 

 would probably extend over ,the thorax and thus correspond to the stripe of the 

 nymph. 



*Clemens '13, p. 336, 



