Calvert: Odonata of the Neotropical Region. 231 



G. d. Sul and i d 1 R. d. Janeiro. The discoidal triangle of the front 

 wings is free in both wings of i c? R. G. d. Sul and one wing 

 female R. G. d. Sul ; both wings of 6 d\ i 9 and one wing cf 

 i c? R. d. Janeiro; both wings of i $ R. Parana; or 20 front wings 

 out of 26, the remaining 6 having this triangle two-celled. There is 

 at least one single cell reaching from M 4 to C x on one hind wing each 

 of 1 c? R. G. d. Sul and of 1 9 R. Parana. 



152. Micrathyria didyma laevigata subsp. nov. 



d\ Agrees with didyma type in size and in the absence of pointed 

 tubercles on the ventral surface of abdominal segment 1. Agrees 

 with didyma hypodidyma in having " the brown stripes on the first and 

 second lateral thoracic sutures so widened that their adjacent edges 

 coalesce almost completely, thus forming one . . . brown stripe," 

 1 mm. wide, "enclosing a green vitta inferiorly," the external or 

 anterior hamular branch " extending forward only to the level of (and 

 not anterior to) the front edge of the anterior lamina." The superior 

 appendages are intermediate between those of didyma type and didyma 

 hypodidyma, being less robust than those of the first, more robust than 

 those of the second, as well as being intermediate in the tendency to 

 form a tooth at the last inferior denticle. There is also the venational 

 difference stated in the table at the head of the genus in this paper. 



Front wings with 12 antenodals, 9-10 postnodals, two posttriangular 

 rows increasing to three at the level of the penultimate antenodal. 

 Hind wings with 8-9 antenodals, 9-10 postnodals, two posttriangular 

 rows increasing to three at the level of the separation of M 3 . 



9. Here I also place individuals from Corumba, in spite of the very 

 different locality from which they come, because they agree with the 

 preceding male in the color character stated, and in the venational 

 characters of the table at the head of this genus, page 229, as well as 

 with the structural female characters of didyma. 



Front wings with 10-12 (11) antenodals, 7-9 (8) postnodals ; hind 

 wings with 8-9 (8) antenodals, 7-9 (8) postnodals. Posttriangular 

 rows as above stated for the male, although the point of increase from 

 two to three rows varies slightly. The only variation from the vena- 

 tional characters of the table of page 229 is that one female has the 

 internal triangle of the left front wing three-celled instead of two-celled. 



Dimensions : Abdomen tf 24.5, 9 21 ; hind wing cT 29, 9 27-29 ; 

 costal edge of stigma, front wing, c? 2.5, $ 2.5-2.8 mm. 



