MICRATHYRIA. 223 
the style-like processes, its apical margin straight; style-like processes about 
‘5 mm. long, one-half as long as lateral margin of 9 ; no mid-dorsal abdominal 
black stripe, only the carina black. Abdomen, ¢ 20-24, 9 19-21; hind 
wing, ¢ 24°5-80, 9 255-27 mm. . . . . . ww we ee ee 6. 8Chumanni. 
EE. Front wing with the internal triangle usually 2-celled ; post-triangular rows 
as stated for schumanni; antecubitals on hind wing 5-6. . Anterior 
lamina more prominent than adjacent parts, bilobed, apices wider (profile 
view), not spinulose but smooth and polished; hamule pointing backward ; 
superior appendages with an infero-internal subbasal denticle. 9. Vulvar 
lamina reaching to one-half of the lateral margin of segment 9, attaining 
the bases of the style-like processes, its apical margin convex, not notched ; 
style-like processes about ‘4 mm. long, one-third to one-half as long as 
the lateral margin of 9; a mid-dorsal abdominal black stripe triangularly 
dilated on the apices of the posterior segments. Abdomen, ¢ 19-21, 
? 16-19; hind wing, ¢ 23°5-25, 9 21-255 mm. . .. ... . . 7% e@qualis. 
EEE. Front wing with the internal triangle free ; antecubitals ou hind wing 6. 
¢. Vulvar lamina and mid-dorsal abdominal stripe as stated for equalis, 
F. The two post-triangular rows, front wing, increase to three rows between 
the levels of the last antecubital and first postnodal. ¢. Anterior lamina 
depressed, constricted in the middle; superior appendages gently curved 
downward at two-fifths their length, with an infero-internal subbasal 
denticle. Abdomen, ¢ 145-16, ¢ 15-17:5; hind wing, ¢ 18°5-20, 
9 20-22 mm... .. . . ee ee ee ew eee) 8 debilis. 
FF. The two post-triangular rows, front wing, only increase to three cells or 
rows at one or two cells distance from the hind margin. ¢. Anterior 
lamina not depressed nor constricted; superior appendages abruptly 
curved downward, almost angulated, at three-fifths their length; no 
inferior subbasal denticle. Abdomen, ¢ 16, ? 14; hind wing, ¢ 20, 
919mm... ........0.0¢.0¢02.0¢6.20¢%260C~U 42 we ee O. CBImiIC. 
Variations in the above venational characters are occasionally met with, and the colour-patterns 
described become obscured with pruinosity in aged individuals; hence the importance of the 
structural, genital, specific characters. 
1. Micrathyria didyma. (Tab. IX. fig. 12.) 
Libellula didyma, Selys, in Sagra’s Hist. Cuba, Ins. p. 453 (1857) *. 
Micrathyria didyma, Kirby, Cat. Odon. p. 41 (1890)’; Calvert, Proc. Calif. Acad. Sci. (2) iv. 
p. 539, t. 17. figg. 98-102 (details, §) (1895) °; Carpenter, Journ. Inst. Jamaica, ii. p. 261 
(1896) *; Ris, Hamburg. Magalh. Sammelr., Odon. p. 35 (1904) ’. 
Dythemis didyma, Hagen, Proc. Bost. Soc. Nat. Hist. xviii. p. 75 (1875) °. 
Libellula phryne (nec Perty), Rambur, Névrop. p. 121 (1842) ”. 
Dythemis dicrota, Hagen, Syn. Neur. N. Amer. p. 166 (1861) *. 
Mesothemis poeyi, Scudder, Proc. Bost. Soc. Nat. Hist. x. p. 194 (1866) ’. 
Additional references, of less importance, are given by Hagen ® and by Calvert’. 
Some, but not all, of the present females from Tamaulipas, Vera Cruz, Oaxaca, Tabasco, and Chiapas, and 
those from Panima and Guayaquil, have the wings more or less tipped with brown. Thus, of the fourteen 
2g 2 
