Caconeura verticalis andamanensis, subsp., 1924

F. C. Fraser, 1924, Report on a collection of dragonflies (Odonata) from the Andaman Islands., Records of the Indian Museum 26, pp. 409-413 : 412

8. Caconeura verticalis andamanensis, subsp. nov.

This interesting species differs from C. verticalis verticalis Selys by not having any transverse red stripe across the head, it agrees, however, in all other respects, size, nodal-index, etc. On the other hand, it agrees with C. verticalis annandalei Fras. in having the head entirely velvety black, but disagrees in its nodal-index, which is 16 postnodals for forewings and 14 for the hind.

This new sub-species thus shares the characters of the two others equally, and is in fact a link form, enabling us to trace the origin of annandalei . C. verticalis extends from Borneo to Burma. This new form is apparently confined to the Andamans, whilst annandalei crops up in the hills south of Madras and extends from thence to the Western Ghats, where it becomes very common. No intermediate forms, nor any of the three mentioned, are known to occur in North India, Assam or North Burma, so that it would appear that the species has spread directly across the Bay of Bengal.