I9I4-] F- F- I/AiDLAW : Odonata. 343 



It differs in having a broader black stripe across the front of 

 the head, and the back of the head black instead of brown, the 

 thorax is entirely brownish-black with numerous fine yellow spots; 

 the whole abdomen is brown, and the legs are of a paler colour 

 than in the male, with a dark mottled line posteriorly. The 

 prothorax has a pair of short forwardly directed spurs projecting 

 from the middle of its dorsal posterior margin. 



This subspecies is one of several geographical races referable 

 to the group Coper a vittata. 



The group is characterized by the anal appendages of the 

 males and according to Forster by the occurrence of dimorphism 

 amongst the females. The female described above is on his view 

 to be regarded as a " virago" form. The females are also remark- 

 able for the possession of the prothoracic spurs. The only other 

 member of the group that I have had an opportunity of examining 

 is C. vittata atomaria, de Selys, from Borneo. 



This subspecies is very closely allied to C. assamensis, and a 

 single female belonging to it is identical in colouring with the male. 

 The group includes the following : — 



C. vittata vittata, de Selys. Malacca. 

 ,, ,, serapica, Hagen. Nicobars. 

 ,, ,, imhricata, Hagen. Sumatra. 

 ,, ,, a/omarm, de Selys. Borneo. 

 ,, ,, assamensis, subsp. nov. Assam. 



" Legion " Agrion. 



38. Onychargia vittigera ? de Selys. 



I cf Dejoo, N. Lakhimpur {H. Stevens). 

 A teneral male, unfortunately lacking the last 4 segments of 

 the abdomen. 



39. Archibasis oscillans (de Selys). (PI. xvi, fig. 3.) 



4 cf o* Dejoo, 3-iv-io {H. Stevens). 

 Length of abdomen 36 mm. 

 hind- wing 25 mm. 



I refer these specimens here with doubt. I have not been 

 able to compare them with an authentic example. 



They show certain differences from de Selys' description which 

 I note below — 



The upper lip is black, not pale. Only one of the specimens, 

 which are all very adult, shows any sign of post-ocular spots; and 

 these are very small. 



The side of the thorax appears to be of a dark greenish-brown 

 with broad blue stripes; but in all it is pulverulent and conse- 

 quently it is not an easy matter to determine the true character 

 of the colouring. 



The first segment of the abdomen is entirely black. 



The lateral view of the anal appendages agree well with de 

 Selys' description of that of the type. Seen from above, however, 



