XIV] CLASSIFICATION 279 



Larva (Mecistogaster) with comparatively short abdomen, and short legs. 

 Mask with triangular projecting median lobe, not incised; lateral lobes and 

 movable hook small; lateral setae present, but not mental. Gizzard with 

 sixteen generalized folds. Caudal gills with the basal portion forming a stalk, 

 the distal portion foliaceous, pointed. 



Subfamily 3. Platycneminae (fig. 145). 



Nodus placed at from one-fourth to one-third of the wing-length from the 

 base. Quadrilateral regular or slightly irregular (the distal angle acute, but 

 not sharply so). C^ not reduced (except in Chlorocnemis). Pterostigma 

 short, regular. No intercalated sectors, except the postnodal one. Ab some- 

 times absent. Tibiae of middle and hindlegs often dilated, especially in the 

 male. 



Larva (Platycnemis) short, rather broad. Mask with projecting median 

 lobe, not incised; mental and lateral setae present. Gizzard of 16 folds with 

 specialized dentition. Caudal gills in the form of thickened lamellae, with 

 long pointed tips. 



Fig. 145. Forewing (21 mm.) of Platy- Fig. 146. Forewing (18mm.) of Coco- 

 cnemis pennipes Pallas, $, Britain. neura solilaria Tillyard, $, Queens- 



Original, land. Original. 



Subfamily 4. Protoneurinae (fig. 146). 



Nodus placed at from one-fourth to one-third of the wing-length from the 

 base. Quadrilateral regular. Pterostigma short, trapezoidal (except Les- 

 toidea). Cu z reduced to a short cross-vein descending to the wing-border; 

 Cu^ sometimes reduced in length. Ab very often absent. No intercalated 

 sectors, except the postnodal one. Small delicate insects with very slender 

 bodies and narrow wings. 



Larva moderately short, with short legs (fig. 42 B, c). Mask flat, without 

 setae. Gizzard with sixteen generalized folds. Caudal gills strongly con- 

 stricted, saccoid or lamellar. 



Subfamily 5. Agrioninae. 



Nodus placed at from one-fourth to somewhat beyond one-third of wing- 

 length. Quadrilateral irregular, with distal angle usually very sharply 

 acute. Pterostigma short, rhomboidal or trapezoidal, rarely abnormal. 

 No intercalated sectors except the postnodal one. Ab always present. 

 Cu z normal. 



Larva of slender build, with short or moderate legs (fig. 42 D, E). Mask 



