ODONATA OF BAJA CALIFORNIA. 515 



3-6 cells wide, from the membranule to the anal angle. 

 Front wings with four rows of post-triangular cells, 12-13 

 antecubitals, lo-ii postcubitals. Pterostigma ochre- or 

 reddish-yellow, 3 mm. long in front wings, 2 mm. long in 

 hind wings. 



Total length 48. Abd. 32. Hind wing 44 mm. 



Dr. Brauer has characterized (I. c, p. 811) the group 

 of T. cofhysa Hag. as having "four discoidal [post-trian- 

 gular] rows, basal spot of the hind wings reaching only to 

 the cross-vein of the middle cell" (^= median cross-vein). 

 This group is divided into two sections, the first with the 

 anal margin of the hind wings entirely or partly hyaline, 

 the second with the anal margin black ; longicauda is re- 

 ferred to the first section. From the sufficiently described 

 species of this first section, the two above males differ as 

 follows : 



Cophysa Hagen has a large quadrangular dark brown 

 spot on the thoracic dorsum, and two, oblique, yellow 

 bands on the sides of the thorax. 



Siibhinotata Brauer has the hamule not projecting be- 

 yond the genital lobe, the sup. app. 6 as long as 8 -|- p-j- 10, 

 inf. app. one-third as long as sup. app., pterostigma longer 

 (3 mm.) on hind wings. 



Longicmida Brauer has the sup. app. 6 as long as 8-f- 

 9+10, the general color of the body and of the basal spot 

 on the hind wings is blackish-brown. These two males 

 may not belong to longicauda, but it seems best to refer 

 them here provisionally. Longicauda inhabits Brazil. 



hisularis Hagen has merely a small hyaline spot on the 

 anal margin of the hind wings, the hamule does not pro- 

 ject beyond the genital lobe, the sup. app. 6 are as long 

 as 8 -i-9-j-io. 



The Mexican and West Indian species abdominalis 

 Rambur which may be considered to belong to the sec- 



