570 EPHEMERINiE. 



Var. ? Pale yellow : head piceous above : thorax with two 

 piceous stripes in front; disk mostly ferruginous: hind borders of 

 the abdominal segments mostly ferruginous : seta? rather more than 

 twice the length of the body; sutures of the joints brownish: fe- 

 mora with two blackish bands : fore border of the fore-wings with a 

 pale yellow tinge, brown for one-third of the length from the tip. 

 Length of the body 4 lines; of the setae 9 lines; of the wings 10 

 lines. 



41. Baetis puscata. 



Picea, subtus ferruginea ; thoracis latera luteo maculata ; pedes 

 ferruginei, antici picei ; alee, limpidce, venis pallidis. Sub- 

 imago ? Testacea ; setce corpore longiores ; alee cinereoe. 



Ephemera fuscata, Barnston, MSS. 



Piceous, ferruginous beneath : antennae black : thorax with 

 some luteous spots on each side : abdomen less than twice the 

 length of the thorax : legs ferruginous ; fore-legs piceous : wings 

 limpid; veins pale, slender; transverse veins indistinct. Sub- 

 imago ? — Dull testaceous : setae pale testaceous, longer than the 

 body : wings gray ; hind borders ciliated. Length of the body 2 — 

 2| lines ; of the wings 6 — 8 lines. 



«, b. St. Martin's Falls, Albany River, Hudson's Bay. Presented 

 by Dr. Barnston. 



42. Baetis scita. 



Nigro-picea, gracilis ; setce albid&, nigro annulatce, corpore multo 

 longiores ; pedes testacei, longi, yraciles, femoribus tibiis et 

 tarsorum articulis apice nigris ; alee limpida, venis nigris, 

 costa venis nigro nebulosis basi nigro-fusca. 



Piceous black, slender : setae whitish with numerous black 

 rings, much longer than the body : legs pale testaceous, long and 

 slender; tips of the femora, of the tibiae and of the joints of the 

 tarsi black ; a blackish band on each femur : wings quite limpid ; 

 veins black, very slender : fore border of the fore-wings blackish- 



