74 MARINE AND FISHERIES 



5 GEORGE v., A. 1915 



merous along the edges of gentle rapids, such as those above "Sandy Gray Falls" 

 on the Musquash River. The nymphs are commonly associated with those of Neu- 

 rocordulia yamaskanensis, Argia moesta putrida and Basiaeschna Janata. 



When ready to transform they climb upon rocks, wharves, boathouses, etc.^ 

 sometimes to a height of five or six feet from the water, but often much nearer. 



As the nymph of Boyeria vinosa was described before B. grafiana had been 

 recognized as a distinct species, (Cabot, '81; Needham '01; Needham and Hart, 

 '01), it is impossible to be certain whether these descriptions all refer to B. vinosa 

 or not, but Needham's description belongs with scarcely a doubt to that species. 



We have reared a number of nymphs of B. grafiana and collected many exuviae 

 as well as nymphs in several localities. We have also received a series of exuviae 

 of a Boyeria from the Shawanaga River, collected by Mr. Paul Hahn, which differ 

 very slightly from those of B. grafiana. The latter were also found on the same river. 

 As vinosa and grafiana are the only North American species of Boyeria and are both 

 common in this region, there can be no doubt that the species not yet reared is 

 B. vinosa. 



The nymphs of these two forms may be separated as follows : 



Mentum of labium 5'5 mm. long, its middle breadth scarcely less than half 

 its length (PL III, Fig. 11) ; fourth abdominal segment without lateral spines; lateral 

 abdominal appendages of female one-fourth to one third as long as the inferior 

 appendages, and usually about as long as the dorsum of segment 10. . . .J5. vinosa, 



Mentum of labium 6-5-7 mm. long, its middle breadth distinctly less than half 

 its length (PI. Ill, Fig. 13) ; fourth abdominal segment generally with distinct though 

 very small lateral spines; lateral abdominal appendages of female one-fifth to 

 one-fourth as long as the inferior appendages and one-half to three-fifths as long 

 as the dorsum of segment 10 B. grafiana. 



B. grafiana also differs from B. vinosa in the slightly stouter inferior abdominal 

 appendages which are less incurved at the tips (Figs. 12, 14) and in the slightly 

 larger size as shown by the following measurement: 



B. vinosa: Length of body 34-36-5; hind wing 6-7-5; hind femur 5-6; 

 width of head 7-5-8. 



B. grafiana: Length of body 37-39; hind wing 7-5-8; hind femur 6-6-5; 

 width of head 8-8-5. 



In coloration the nymphs of these two species are quite similar, except that the 

 pale, wavy, dorso-lateral streak on each side of the abdomen is usually quite dis- 

 tinct in grafiana but more or less obscure in vinosa. In both species the depth of 

 coloration varies considerably, usually being a rather dark brown. All the nymphs 

 from the Go Home Bay district are very dark in colour, but the pale bands of the 

 abdomen and legs are quite sharply defined. The most characteristic mark of 

 Boyeria nymphs is a pale oval or diamond-shaped median blotch in the dorsum of 

 segment 8. 



Basiaeschna Janata Say (Selys). 



This species considerably resembles the preceding in its habits both in the 

 nymph and adult states, but flies during the first instead of the second half of sum- 



