Odonata from New Caledonia. 63 



Nymph of Si/nthemis sp. 



New Caledonia, 1914 (exact data not preserved). 



Tlie divergent wing-cases and general foriu of this nymph 

 proclaim it to be a member of the Synthemini, the first of 

 its kind to be found in New Caledonia. Most probably it 

 belongs to one of the large species of Syrithemis which have 

 just been considered, although it is not possible to associate 

 it with any particular one of them. Unfortunately, a 

 preparation of the rudimentary wings, made by my friend 

 Mr. James Waterston, reveals nothing beyond the fact that 

 the venation is in too undeveloped a condition to afford any 

 guide to specific identification. 



While the imagines of the three large species from New 

 Caledonia are most nearly allied to Synthemis regina, the 

 single Oceanic nymph is like that of Eimjuthemis guttata in 

 having the median lobe of the labium produced anteriorly 

 and a conspicuous semicircular plate projecting from the 

 frons. In other ways, however, our specimen fails to agree 

 Avith that or any other known nymph of the Synthemini, f or 

 the body is relatively smooth, instead of being distinctly 

 hairy, and the long setfe on the lateral lobes of the mask are 

 exceptionally few in number. 



The presence of a frontal plate in nymphs of Eusynthemis 

 is one of the principal characters employed by Tilly ard for 

 distinguishing that genus from Synthemis, and the occurrence 

 of such a plate in an undoubted Synthemis nymph would 

 show that the character cannot be used for generic separa- 

 tion in the manner proposed by that author. Iiuleed, the 

 characters of the genera Synthemis and Eusynthemis tend to 

 overlap, not only in the nymphs, but in the imagines as 

 well. For exam|)le, Eusynthemis nigra is a Synthemis, if 

 judged by the shape of the abdomen, while Synthemis sjnui- 

 gera is a Eusynthemis, in respect of the armature of the 

 superior anal appendages. Two characters which remain 

 valid for Synthemis are the long anal appendages of the male 

 and the retention of the ovipositor in the female. 



Description : — 



Length, excluding antennae, 28 ram. 



Not conspicuously hairy. 



Mask yellowish brown ; in position of rest, reaching back- 

 wards to a point between the bases of the mid and hind 

 legs ; terminal hook.s fully exposed ; median lobe advanced 

 to a distinctly protruding point ; distal border of lateral 

 lobes with 5 distinct teeth on right side and 6 on left side ; 

 primary mental setai, 7 on right side and 8 on left ; secondary 



