112 Annals Entomological Society of America [Vol. IV, 



Abdomen, beneath, brown without markings. Setae 3, with a circlet 

 of spines at their joinings. A broad band of brown across the two outer 

 ones. 



Ephemerella lata, sp. nov. 

 Occurrence, habitat. This species was first taken in Sandy 

 River, Me., a stream similar to Fall Creek, where it was very 

 common. Attempts to rear these nymphs were unsuccessful 

 in both Sandy River and Fall Creek therefore a description of 

 the nymph only can be here included. It occurs in the most 

 rapid water of the stream crawling on the stones much like 

 Heptagenia. My dates for its capture in Fall Creek are 

 June 20 and 24. It is apparently a rare species in the stream. 



Measurement. — Nymph. Length of body 7.2 m.m. Length of 

 setae 3.5 m.m. 



Nymph (PI. VI, fig. 6; PI. VII, fig. 1). General color brown with the 

 prothorax and the eighth tergite conspicuously white. The fore femora 

 very stout (PL VI, fig. 6) and edged with stout spines. Body arched 

 above. The ventral side of the body and the legs flattened and modified 

 for clinging to smooth surfaces. Head, sub-quadrangular with the 

 broad truncate ledge projecting forward above the rounded heavily 

 fringed frontal border (PI. VI, fig. 0). Antennae with a conspicuous 

 triangular ledge projecting above their bases. (Mouth-parts are figured 

 on PI. VIII, fig. 1). Thorax, prothorax two-thirds as long as the thorax, 

 conspicuously whitish but with the posterior portion shaded brownish, 

 the degree varying in different ages and individuals; mesothorax with- 

 out markings; metathorax concealed from above. Sternum flattened, 

 brown with pale suture lines. Legs (PI. VII, fig. 1) with the femora 

 pale marked by a pale transverse band; tibiae brown with two pale 

 transverse bands. Abdomen, rounded above, flattened below. Gills 

 on segments 3-8. Elytroid cover absent. Segments 4-9 with their pos- 

 terior lateral angles produced backward into flat spines; segments 5-8 

 with their lateral margins spinose serrate; segments 4-7 with a double 

 median row of small tubercles which arise near the posterior border. 

 Sternite 9 produced backward into a median rounded lobe and two lateral 

 flat spines. Setae 3, light brownish ringed at their basal joinings with 

 darker brown. 



Ephemerella tuberculata, sp. nov. 

 Occurrence, habitat. But a single specimen of this species 

 has been taken. This was a nymph captured on June 22 in the 

 gently flowing border water of the upper Creek. 



Nymph, measurements. Length of body, 10.5 m. m.; length of 

 setae, 4.5 m. m. 



Body stout arched above, flattened below. Color above dark, 

 below pale, with a median double row of distinct brown spots. Fore- 

 femora very wide (PI. VII, fig. 5). The head (PI. VI, fig. 2) with two 



