250 PHILIP p. CALVERT. 



%. Hind luargiti of occiput slightly concave. Sup. app. abruptly narrowed on 

 inner side just before the apex, which is rather truncated and prolonged on the 

 outer side into a sharp spine. Inf. app. one-sixth as long, quadrangular, wider 

 than long, upper surface with a subiuedian tooth and many smaller apical teeth 

 each side. 



9 • Hind margin of occiput elevated and emarginated in the middle. 



Abd. % 53.5-56, J 52-56. H. w. % 46.5-56, 9 48-56. 



Common arouiul Phila., earlier than May 1 — Oct. 16; in copula 

 or ovipositing May 1, June 15, 19, 22, 28, July 6. 



Quebec to Florida, west to the Pacific, Alaska to Costa Rica, W. 

 Indies, Sandwich Is., Kamtschatka, China. 



.Viiax loiigipes Hagen, recorded from Brazil, West Indies, Mexico, Florida, 

 Maryland, Massachusetts, has the frons green, unspotted superiorly, in both 



sexes. 



Subfamily 6. CORDULINiE. 



22. Didyniops Rarabur. 



Ramb., Ins. Nevr. p. 142, 1842. Selys. Bull. Ac. Belg. (2) xlv, p. 211, 1878. 

 87. Didyiuops transversa Say. 



Lihdlula t. Say, .Tour. Ac. Phila. viii, p. 19, 1839. Macromia t. Selys, Bull. Ac. 

 Belg. (2) xxxi, p. 548, 1871. 



Grayish to brown. Nasus and frons above yellow, the latter with a superior 

 black T-spot. Thorax with a small antehumeral spot {sometimes absent), an ob- 

 lique, mid-lateral baud, and the antealar sinuses, pale yellow or white; no hu- 

 meral stripe. Abdomen quite slender in the middle, thickened at 7-10, 2-8 with 

 a spot each side of dorsum and 10 entirely, yellow. A small yellow or brown 

 basal cloud at base of front margin of wings. 



%. Sup. app. longer than 10, denticulated below, extreme apex directed up- 

 wards and outwards. Inf. app. of equal length, broad, triangular. 



9 . Vulvar lamina very short, emarginated in a semicircle. 



Abd. I 36-38, 9 38-40. H. w. % 31-35, 9 38-39. 



One male, Wissahickon, Phila., May 20, 1883, S. F. Aaron ; one 

 male, Fairmount Park, May 31, 1891, Dr. H. Skinner; one male, 

 Mt. Holly, N. J., May 13, E. M. Aaron (A. E. S.). One male, Ar- 

 eola, Montgomery Co., Pa., May 19, 1893, P. Nell (C). 



Quebec to Georgia; Michigan, Kentucky, Texas (Provancher, 

 Miss Wadsworth, Harvey, Cabot). 



23. Macromia Rambur. 



Ramb. Ins. Novr. p. 1.37, 1842. Selys, Bull. Ac. Belg. (2) xlv, p. 210, 1878. 

 38. 9Iacrotnia tseniolata Rambur. 



M. t. Ramb. I. c. p. 139, 1842. Epophthalmia t. Selys, I. c. (2) xxxi, p. 527, 1871. 



Blackish, with more or less metallic reflection. Frons above metallic blue, 

 with two small yellow spots in front of the vertex. The following yellow: a 

 transverse nasal hunA, a short ante^iumeral stripe, & broad baud entirely around 



