424 NEW YORK STATE MUSEUM 



1863 B a e t i 8 a 1 1 e r n a t u s Walsh, Ent. soc. Phil. Proc. 2 : 189 

 1853 Baetis annul a ta Walker, List Neur. ins. Biit. mus. 3 : 567 

 1861 Baetis annulata Hagen, Synopsis Neur. N. Am. p. 48 



1876 Baetis femorata Provancher, Nat. Canadienne. 8 : 267 



1877 Baetis femorata Provancher, Faun. ent. du Canada. 2 : 83 



1871 Siphlurus annulatus Eaton, Ent. soc. Lond. Trans, p. 127 (de- 

 scription in Latin: figures of forceps of male, and ventral abdominal 

 markings in pi. 6, fig. 4 and 4a) 

 1871 S i p h 1 uru s al t e rn a tu s Eaton, Ent. soc. Lond. Trans, p. 129 

 1877 Siphlurus alternatus Provancher, Faun. ent. du Canada. 2 : 83 

 1885 Siphlurus alternatus Eaton, Linn. soc. Lond. Trans. (2) 3:219 

 1892 Siphlurus alternatus Banks, Am. ent. soc. • Trans. 19 : 346 (listed) 



This handsome brown species was not observed at large, was not 

 taken in our trap lanterns, and was only obtained by rearing nymphs. 

 These were not uncommon in shallow water about the outlet of Little 

 Clear pond among the debris of fallen brushwood. Doubtless the imagos 

 might have been found at large, had careful* search been made of the 

 shores about these same places. 



The nymph is a graceful creature, and exceedingly agile. The 

 beautiful fringes on the abdominal setae constitute a powerful tail fin, 

 one stroke of which sends the nymph through the water with a speed 

 the eye can hardly follow. It is exceedingly difficult to pick up one 

 of the nymphs, when confined in a little dish of water, with a forceps, so 

 quickly will they dart away. In a water net of some size they are easily 

 taken, however, apparently not finding themselv.es ensnared till lifted 

 from the water. A good many specimens were taken in shallow water 

 behind a large hummock overgrown with cattails (Typha) to the 

 north of the outlet of Little Clear pond. These transformed July 21, 

 22 and 23, and remained in the subimago stage for more than 48 hours 

 in every case, undergoing the final molt during the second day after 

 emergence from the larval skin. 



This species is widely distributed throughout the eastern United States. 



Nymph. PI. 11, fig. 5, 6 Length of body 15 mm; setae 6.5 mm 

 additional; abdomen 9.5 mm; antennae i mm. 



Body arched, tapering, very graceful and exceedingly well adapted for 

 swimming. Abdomen somewhat depressed and upcurved at the tip. 

 Face vertically elongated, with an aspect singularly like that of the face 

 of the common grasshopper. 



Head and prothorax short, each about twice as wide as long; meso- 

 thorax large and prominent; abdomen a little wider in the middle, 

 tapering slightly to the end, serrated on each side by the prolongation 

 of the posterolateral angles of segments 1-9 in sharp, single, back- 

 wardly directed teeth, which become largest on the sides of the 8th 

 segment, and sharpest and thinnest on the sides of the ninth: loth 

 segment cylindric, two thirds as wide as the ninth. 



