+ PROCEEDINGS OF THE NATIONAL MUSEUM. VOL. 62. 
especially because it is evident that the genera of the Brachytron 
series requires careful revision, as does the synonymy of some of the 
species. 
DISTRIBUTION. 
The accompanying diagram will, I hope, serve to show at a glance 
the distribution of some of the more characteristic forms. If it be 
compared with a map showing the average yearly rainfall it will at 
once be evident that many of the genera seem to be especially 
dependent on a very copious rainfall for their existence. With this 
is perhaps to be correlated an observation I made whilst in the Malay 
Peninsula; that some of these insects seem to select for breeding 
KASHMIR. 
PALAEARCTIC REGION 
PALAEARCTIC 
RECION SETHE — eel 
Wagoria Austroaeschna P 1 JAPAN 
PERSIA. {PeriaeschnaAeschna spp. CHINA . pieriatschoe | Jagoria 
| _ASSAM & Cephalaeschna 5, 2: haa” 
Seta a | UPPER BURMA. Anaiineueclivene aca iets 
is, aculll fons f 
INDIA. [‘Cephalaeschna ; read ji 
| 
ATs BN eR “| sete |_FORMOSA. 
Anax immaculifrons : 
LOWER BURMA. HAINAN | Planaeschna 
{| 
Heliaesehna 
S.INDIA - 
LOWER SIAN . Periaeschna 
Amphiaeschna Am phiaeschna 
Tetracanthagyne 
“Tetraeanthagyna 
SONDAIC ISLANDS. PAPUA. 
CELEBES. 
Heliceschna 
Jagoria 
Tetracanthagyna 
Heliaeschna 
Fic. 1.—IN THE ABOVE DIAGRAM THE BOUNDARIES OF A REGION ARE MARKED BY A DOUBLE LINE. THE 
DEGREE OF DIFFERENTIATION BETWEEN AREAS WITHIN THE REGION IS INDICATED BY A SINGLE LINE OR 
BY A DOTTED LINE, ACCORDING TO THE CLEARNESS OF DISTINCTION OR OTHERWISE. SIMILARLY, THE 
BOUNDARIES OF THE REGION, WHERE THESE ARE NOT CLEARLY DEFINED, ARE MARKED BY A SINGLE 
LINE OR BY A DOTTED LINE. ONLY THE MOST CHARACTERISTIC GENERA ARE ENTERED. 
purposes quite small pools, one might almost call them puddles, 
which are only kept supplied with water by rain. Nor are dragon- 
flies by any means the only creatures which lay their eggs in such 
exiguous nurseries. I remember more than once finding frog-spawn 
in depressions little larger than a foot print, hopelessly dessicated 
with a few hours of sunshine. 
CHARACTERIZATION OF THE SUBFAMILY AESCHNINAE. 
Triangles of fore and hinder wing approximately equal, longitu- 
dinally elongated; subtriangles weak or absent. Radial and median 
supplements present. Two reinforced antenodal costal cross-nerves. 
