280 



CLASSIFICATION 



[CH. XIV 



with projecting median lobe, not incised; mental and lateral setae present. 

 Caudal gills usually slender lamellae, mor.e or less pointed, and held in the 

 vertical plane; either distinctly nodate, subnodate, or secondarily simple. 

 Secondary tracheae placed obliquely to the gill-axis. Gizzard of 8-16 fields, 

 with specialized dentition. 



Tribe 1. Argiini (fig. 147). 



Wings only petiolate to level of Ax v Ac falls on to A' at a point slightly 

 distad from the distal end of the petiole. Moderately robust forms. Legs 

 with long bristles. Larva with caudal gills short, thick, simple. 



Fig. 147. Hind wing (22 mm.) of 

 Argin apicalis Say, ?, N. America. 

 Original. 



Fig. 148. Forewing (19 mm.) of 

 Agrion pukhettum Vand.. $, Britain. 

 Original. 



Tribe 2. Agrionini (fig. 148, also PI. I, fig. 9). 



Wings more petiolate than in Tribe 1, to between levels of Ax 1 and Ax 2 . 

 Ac falls on to A' at a point slightly distad from the distal end of the petiole. 

 Slenderer forms. Legs with short or moderate bristles. Larva with caudal 

 gills variable, nodate, subnodate or denodate, usually fairly long (rarely 

 reduced and non-functional). Gizzard with sixteen specialized fields. 



Tribe 3. Pseudagrionini (fig. 149, also PI. II, fig. C). 



Petiolation of wings as in Tribe 2. Ac falls on to the angle between the 

 petiole and the curved portion of the posterior border of the wing, or slightly 

 proximad to it; hence A' is completely fused with the wing-border. Slender 

 forms. Larvae as in Agrionini, but gizzard sometimes with only eight fields 

 carrying large teeth (Caliagrion). 



Fig. 149. Forewing (20 mm.) of Pseud- 

 agrion aureofrons Tillyard, $, New 

 South Wales. Original. 



Fig. 150. Forewing (25 mm.) of Teino- 

 basis rufithorax Selys, $. Torres 

 Straits. Original. 



Tribe 4. Teinobasini (fig. 150). 



Wings very slender, petioled almost to level of Ax z . Ac falls as in Tribe 3. 

 Ms and M 3 arise exceedingly close together. Extremely slender forms. 

 Tarsal claws reduced, without an inferior tooth. Larva unknown. 



