THE CANADIAN ENTOMOLOGIST. 375 



hooks on segments 4-8, straight, or but slightly curved, rudimentary 

 on 4, increasing to 7, on which the hook is almost as long as the 

 segment; lateral spines on 8 and 9, on 8 about one-fourth (measured 

 on the inner margin) as long as the lateral margin of the segment 

 (without spine) ; on 9 about one-third to one-half as long as the 

 lateral margin, not quite reaching the level of the ends of the 

 lateral appendages, which are about two-thirds as long as the 

 superior appendage, and slightly more than one-third as long as 

 the inferior appendages. Superior appendage slightly longer than 

 broad; both superior and inferior appendages acuminate, termin- 

 ating in very slender apices. 



Colour greenish brown, with rather obscure dark markings. 

 Thorax with a dark longitudinal band on the pleura; femora dark, 

 with two pale annuli, a median and an anteapical; tibia? also with 

 two pale annuli separated by a median dark annulus. 



Length of body 16-18; outer wing-pad 5-6; hind femur 4.6-5; 

 width of head 4.5-4. 9; width of abdomen 5. 5-6. 



As already stated, the nymphs of pallipes and costiferum are 

 practically indistinguishable. The only differences I could find 

 are the slightly greater basal width of the mentum of the labium 

 in costiferum and in the spines on the distal margin of the lateral 

 lobes of the labium, which in costiferum are usually single or with 

 only one additional rudimentary spinule. 



Leucorrhinia hudsonica Selys. 

 On June 18-20 adults of this species were found in considerable 

 numbers at Nipigon, Ont., where they were associated with L. 

 glacialis, although much more numerous. No other Libellulines 

 were as yet abroad, the only other Anisopterous dragonfly being 

 Cordulia shurtleffi. Both L. glacialis and C. shurtleffi were trans- 

 forming in the marshy borders of the Nipigon River, but careful 

 search failed to result in the finding of a single nymph or trans- 

 forming imago of L. hudsonica. Two exuviae were found, how- 

 ever, which can belong to no other species. 



Nymph (pi. XXV, figs. 9-12). — Similar in form and size 

 to L. frigida; head similar, but the eyes somewhat less 

 prominent, more as in intacta (see Canadian Entomologist, 

 45, 1913, pi. 2, figs. 20, 23); rear of head with numerous 



