90 Proceedings of the Biological Society of Washington. 



between Mj and Mg become double; below middle of stigma the supple- 

 mentary vein below Mi begins, and below end of stigma the cells between 

 it and Mj become double, while those between it and M2 are in three 

 rows from level of middle of stigma; below the stigma M2 is separated 

 from Ks by three rows of cells. Rs is separated from the supplementary 

 vein below it by at least four rows of cells, as is seen in No. 8636, which 

 shows the part of the wing immediately basad of that preserved in the 

 type. In 8636 the stigma is only 4.5 mm. long, and is bounded by three 

 cells below. 



No. 8590 exhibits the triangle and adjacent parts, and appears to belong 

 to 0. vectensis. The triangle is 2.25 mm. long, five celled, formula 

 2, 1, 1, 1. It is formed as in 0. separata Scudder, from the Florissant 

 Miocene. The base of the triangle is bounded by one cell and a minute 

 fraction of a second. The branches of the media arise below the middle 

 of the arculus. Basal space without cross-veins. 



Gurnet Bay (Brodie). British Museum, 8572 (type), 8636, 8590. 



By the number of cells between R3 and the supplementary vein below, 

 this resembles the European (Radoboj) fossil 0. metis (Heer) and the 

 Florissant 0. lapidaria Cockerell and Counts. The triangle and adjacent 

 parts resemble those of 0. separata, and especially 0. lapidaria. The 

 long {,Boyeria-\i\ie) stigma also associates the species with 0. lapidaria, 

 not with the living 0. armata. 



Megalestes anglicus Cockerell. Fig. 5. 



Megalestes (?) anglicus Cockerell, Proc. U. S. Nat. Mus., 49 (1915), 

 p. 498. 



This name was based on part of the basal half of a wing, but a speci- 

 men now before us (Gurnet Bay, Brodie; Brit. Mus. 8548) appears to 

 represent the apex of the wing of the same species. It has in general the 

 characters of Megalestes major Selys, but the light brown pterostigma is 

 more produced apically, its apical margin being long and very oblique, 

 the apical point forming an angle of about 45°. The stigma therefore 

 approaches the condition which is more exaggerated in Amphipteryx, but 

 it is to be noted that the basal side remains quite unmodified from the 

 Megalestes type. There are five simple cross-veins beyond the stigma, 

 and the costal cells between the stigma and nodus are much longer than 

 high. The ultranodal sector (between Mj and Mg) begins only seven 

 cells (in longitudinal row) basad of level of stigma; it is straight (not 

 zigzag as in Lestes). Length of stigma about 2.3 mm. 



Enallagma oligocena new species. Figs. 6, 7. 



The type (Gurnet Bay, Brodie; Brit. Mus. 8631) consists of the bases 

 of both wings. In the division of the Coenagrionines on the character 

 of the postcosta, this falls entirely with Enallagma and the related genera, 

 the postcosta leaving the margin of the wing at a distance from the basal 

 postcostal cross-vein much greater than the latter is long (the actual dis- 

 tance, in the hind wing, is about 880 /u, the length of the cross-vein being 



