ArT. 21. DRAGONFLIES OF BURMA AND LOWER SIAM—LAIDLAW. 19 
has the female very remarkable anal appendages, but there are well- 
marked venational characters, notably the short triangles, and the 
course of the supplements almost parallel to Rs and M,, respectively 
(according to Martin’s figure), which differentiate the species strongly 
from other Aeschnas. 
The two remaining species do not appear to be particularly closely 
related to other species of Aeschna, nor indeed to one another, 
though they show one peculiarity in common. In both species the 
apex of the dentigerous plate of the female carries a series of regu- 
larly arranged denticles radiating from the apical margin. In the 
case of all the other species of the genus that I have examined the 
dentides are arranged irregularly and on the ventral surface. 
A. erythromelas MacLachlan is a large and handsome species found 
in northeast India and Tonkin. The hinder wing has a length of 
55 mm. The thorax in both sexes is reddish-brown, with green 
antehumeral and lateral bands. The abdomen has segments 1-7 
brown with small median and terminal markings of yellow on each. 
Segments 8-10 are black. The upper anal appendages of the male 
are spatulate. A. ornithocephala MacLachlan from Assan and the 
northeast Himalaya is smaller, the hinder wing having a length of 
48 mm. The venation is open, and the triangle shorter than is usual 
in the genus; the pterostigma is small, 3 mm. long. The anal append- 
ages of the male somewhat resembles those of the Japanese A. melan- 
ictera Selys and as in that species the male has a prominent spur on 
the dorsum of the tenth abdominal segment. Doctor Annandale 
has observed females of this species ovipositing in the muddy banks 
of small pools on the Himalayas, some feet away from the water. 
LIST OF ORIENTAL SPECIES OF GENUS AESCHNA. 
1. A. petalura Martin: Northeast ranges of the Himalaya and Assam? 
2. A. erythromelas MacLachlan: Northeast India, Tonkin. 
3. A. ornithocephala MacLachlan: Assam and northeast Himalaya. 
Genus GYNACANTHA Rambur.® 
A good account of the oriental species of this rather difficult genus 
was given by Kruger in 1898. 
He listed the following species: G. furcata Rambur, subinterrupta 
Rambur, rosenbergi Brauer, hyalina de Selys, basiguttata de Selys, 
nigripes de Selys, bayadera de Selys, limbalis Karsch, musa Karsch, 
dohrni Kruger, maclachlani Kruger, 11 species in all. Of these ros- 
enbergi almost certainly does not occur within the limits of the region, 
and nigripes is arace or color variety of MacLachlan’s species khasiaca. 
8 Since these notes were sent to press Fraser has described three new species of this genus; one from 
Bengal, G, o’doneli (Journ. Bombay Nat. Hist. Soc., 1922, vol. 28, p. 700) is allied to millardi but isemaller ; 
two others bainbriggei and hanwmana (Mem. Dept. Agric. India, Ent. Ser., vol. 7, no. 7, p. 75 and 76 respec- 
tively) come from the Himalayas. 
60466—23—Proc.N.M.vol.62——_ 47 
