220 F. F. LAIDLAW. 
The following measurements serve to show the differences in size between specimens 
from the two localities. 
Average length of fore-wing of males from Minikoi 38 mm. 
male » Hulule 34 mm. 
‘. a - female ,, Minikoi 37°5 mm. 
i ie A Fe »  Hulule 30 mm. 
: abdomen of female from Minikoi 28 mm. 
x . $3 s »  Hulule 19 mm. 
» ” ” 
In the male from Hulule there is a dark spot covering the triangle and supra-triangular 
space of the fore-wing, in the Minikoi specimens this dark mark is confined to the triangle. 
On the hind-wings of the former specimen there is on either side an irregular transverse 
dark band running from the nodus to the hind margin, in the latter this is represented 
only by scattered patches of colour. 
The yellow on the wing of the female specimen from Minikoi is more intense and 
extends further than on the wing of that from Hulule. 
The neuration of the two forms agrees closely. 
4, TRITHEMIS (?) TRIVIALIS (Ramb.). 
Trithemis trivialis Kirby, Cat. Odonata, p. 18. 
8 ¢, 7 & labelled Minikoi. 
1 g, 1 3 labelled Maldives. 
The length of the fore-wing in the largest male is 285 mm., in the smallest 26 mm. 
The abdomen measures 22 mm. and 19°5 mm. respectively. The average length of the male 
fore-wing is about 27°5 and of the abdomen about 21mm. The females vary less in size. 
In them the average length of the fore-wing is 27 mm. and of the abdomen 21°5 mm., and 
the range of variation from the average does not exceed a millimetre. 
These specimens are considerably larger than specimens in the British Museum from 
Ceylon, an average male specimen from the latter locality measured about 22 mm. along 
the fore-wing, whilst a female of the same species from Christmas Island had the fore-wing 
about 21°5 mm. in length. 
In Mr Gardiner’s series of this species the average number of costal antenodal nervules 
is 8, the last not being continuous. In two males and three females there is a super- 
numerary antenodal on the fore-wing of one side or the other, in most cases interpolated 
between the 6th and 7th antenodal and not continuous. The largest specimen, a male, has 
8 continuous antenodal and a terminal non-continuous antenodal on both fore-wings. The 
smallest specimen has 8 antenodals in all on both fore-wings. The usual number of post- 
nodals on the fore-wings is 6. In the largest male and in two other large specimens there 
are 7 on both sides, and in four other cases there are 6 on one side and 7 on the 
other, the remainder including the smallest specimen have 6 on both sides. Thus the 
largest specimen has the maximum number of costals on either fore-wing, viz. 16, whilst 
the smallest specimen, also a male, has the minimum number, 14. 
