376 THE CANADIAN ENTOMOLOGIST. 



long hairs. Mentum of labium almost as broad distally as long; 

 sides nearly straight on the proximal two-thirds, thence bending 

 outwards so as to be rectangularly divergent. Ventral surface in 

 the proximal two-thirds somewhat longitudinally convex; median 

 •lobe depressed at an angle of about 30 ; apex but little rounded. 

 Mental setae 12-14; the third to the fifth from the outside longest. 

 Lateral setae 9 or 10; movable hook slender, nearly half as long as 

 distal margin of lateral lobes, the latter slightly undulate, the 

 spines single or, here and there, a pair, of which the upper is much 

 shorter than the lower; there may be also a third very rudimentary 

 spinule on the opposite side of the long spine (fig. 12). 



Abdomen, as in other species of the genus, broad-ovate, 

 widest at segment 6, narrowed almost equally toward apex and 

 base. Dorsal hooks on segments 3 oi 4 to 6, vestigial, longest on 

 5. In one specimen they are considerably better developed than 

 in the other, there being quite a distinct hook on segment 3, while 

 in the other there is no trace of a hook on this segment. In the 

 former the hook on 5 reaches the hind margin of the segment, in 

 the latter it does not nearly reach the margin. Lateral spines on 8 

 about two-fifths the length of the segment, slightly divergent; 

 spines on 9 about three-fifths the length of the segment, reaching 

 to the level of the apex of the lateral appendages, their inner 

 margins parallel; superior appendage about three-fourths as broad 

 at base as long, sides nearly straight, apex acuminate, slender, 

 somewhat decurved ; lateral appendages rather stout, but tapering 

 rather abruptly to fine-pointed apices, about three-fifths as long as 

 the superior appendage and half as long as the inferior appendages, 

 which project a little beyond the former. The setae on their inner 

 surfaces are longer and coarser than in L. frigida. 



Colour dull brownish above with faint indications of mottling, 

 but no distinct pattern. Legs apparently without distinct annuli. 

 Under surface of abdomen with three conspicuous, dark brown, 

 longitudinal bands. 



Length of body 17-17.5; outer wing-pad 5.3-5.5; hind femur 

 4.3-4.4; width of head 5-5.2; width of abdomen 6-6.2. 



These nymphs differ from the form described by Needham as 

 belonging to L. frigida only in the presence of vestigial dorsal hooks, 

 which in Needham's specimens are wholly lacking. I have a 



