278 . NEUROPTERA. 
sector”); its presence in Brechmorhoga means that the two post-triangular rows on the 
front wing usually increase to three rows well proaimal to the level of the nodus, while 
in Macrothemis its absence is associated with the condition that the increase from two 
to three post-triangular rows takes place distal to the nodus-level. As to the point 
where this increase from two to three rows takes place, 14°/, of 186 front wings of 
Brechmorhoga (exclusive of inequiunguis) vary toward Macrothemis, nearly 8°/, of 294 
front wings of Macrothemis vary toward Brechmorhoga. A widening of the post- 
triangular area at the wing-margin occurs in some Macrothemis even where this area 
otherwise conforms to Mr. Kirby’s description just quoted. 
On the whole, I have preferred to separate these two closely-allied genera by the 
character of the tarsal claws (anted, pp. 201, 202). As a result, I am obliged to 
transfer to Brechmorhoga the species which I originally described as Macrothemis inequi- 
unguis, although its venational features correspond with Mr. Kirby’s Macrothemis. 
The additional material has also rendered the separation of the species much more 
difficult. Features which alter with age appear to be, in some species, the extent of 
metallic-blue on the frons, of black on the labrum, and of dark colouring on the sides 
of the thorax. I have therefore sought to rely upon characters not so subject to 
change in the life of each individual, such as the shape and proportions of the genitalia 
and the venation. The forms of Brechmorhoga which bear specific names below do 
not seem to be as distinct from each other as those of Dythemis are. 
It is worth mentioning that no pruinose individuals are to be found in the 
Brechmorhoga which I have studied, although such frequently occur in Dythemis 
and in Macrothemis. 
Synopsis of the Mexican and Central-American Species. 
A. Internal triangle of the front wing 2- or more celled. 
B. Males having the hind wings with two post-triangular rows from the 
triangle out; or, in some, with a single cell reaching the entire distance 
across from the short sector to the first sector of the triangle, followed 
immediately by two rows; genital lobe as prominent as the anterior 
lamina; superior appendages with inferior denticles, but no tooth. 
Females with the eleventh abdominal tergite (“ anal tubercle ”’) -5—-7 mm. 
in length, half as long as the abdominal appendages, hairy, rounded at 
tip. Pale spot on each side of dorsum of abdominal segment 7, in both 
sexes, at least almost half as wide as each side. 
C. Hind wings with 2(¢), 2-8 (2) rows of cells between the proximal 
sub-basal sector (A; of C. & N.) and the wing-margin posterior to the 
membranule *, 8°5-10 mm. wide at the arculus and at the nodus; 
abdomen of the males longer than the hind wing. 
* All Brechmorhoga spp., 3 2, have three rows of cells between A, and the membranule and for usually 
