1913.] NATURAL SCIENCES OF PHILADELPHIA. 257 



B. — Antenodals more than two on all the A\-ings, or on the hind wings 

 only (Neuragrion). (See also the parenthesis following rubric 

 BB.) 

 C. — Area posterior to Cu2 with three or more rows of cells, A 

 separating from the hind margin proximad to the level of the 

 arculus, Rs l^eginning at the subnodus. 

 D. — Quadrilateral oblique at distal end. 

 E. — Supplementary sectors between M* and Cui absent; between 

 :\Iio and :\I2 five, between Rs and Ma eight rows of cells, 



respectively Dysagrion Scudder, 1878 (Eocene, Wyoming). 



EE.— Supplementary sectors between M4 and Cui three or four; 

 between Mia and M2 three, between Rs and Ms three rows 



of cells respectively 



Phenacolestes Cockerell, 1906 (Miocene, Colorado). 

 DD. — Quadrilateral almost rectangular at both proximal and distal 



ends; many supplementary sectors from Mi to hind margin 



Thaumatoneura :\I'Lachlan, 1897 (Central America). 

 €C.— Area posterior to Cu2 with only one row of cells, A separating 

 from hind margin at or distad to the level of the arculus. 

 F. — Us beginning at subnodus, supplementary sectors from 



Mia to ]\l4, two or more cubito-anal cross-veins 



Neurolestes Selys, 1882 (West Africa). 

 FF.— Rs beginning distad to the subnodus, supplementary 



sectors from Mia to Ma, one cubito-anal cross-vein 



Neuragrion Karsch, 1891 (Ecuador). 



BB. — Antenodals two only (more than two have been noted in 



occasional specimens of Podopteryx, a genus included under 



this rubric). 



G. — Rs beginning proximad to the subnodus. 



H. — Area posterior to Cu2 with two rows of cells, A separating 



from the hind margin proximad to the level of the 



arculus, supplementary sectors from Mia to M4 



Melanagrion Cockerell, 1907 (Miocene, Colorado). 



HH.— Area posterior to Cu2 with one row of cells, A separating 



from hind margin distad to the level of the arculus, 



supplementarv sectors from Mia to Cu2 



Rhipidolestes Ris, 1912 (Formosa). 

 GG. — Rs beginning at the subnodus. 



J.— Area posterior to Cu2 with 4-5 rows of cells, A separating 

 from the hmd margin at or distad to the level of the 



arculus, supplementary sectors from Mia to Cui 



Podopteryx Selj's, 1871 (Aru, Queensland). 

 JJ. — Area posterior to Cu2 with 2 rows of cells, otherwise as 



in Podopteryx 



Argiolestes Selys, 1862, sens, strict.^^ (Australian region). 



89 As here limited includes only the groups IC and 2 of Selys' Revision of 1886, 

 p. 81. See the remarks of Martin on the variability of the points of departure 

 of Ms and R^ in Argiolestes, Boll. Soc. Ent. Ital, Ix, p. 201, 1909. 



