(syn. Todiramphus Ϯ Blue-black Kingfisher T. nigrocyaneus) Gr. δι- di-  double  < δις dis  twice  < δυο duo  two; genus Lazulena Mathews, 1918, kingfisher (cf. Med. L. lazulus  azure, deep-blue); "Another closely allied series of purple-backed Kingfishers again show structural differences, while the colour has not essentially changed. They are bigger birds with broader, stronger bills, still of the same coloration as those of Lazulena, with the tail longer and more graduated. The wing-formula is essentially different, the first primary being short and the secondaries being long, exceeding it in length: the first primary is less than the ninth, the second a little longer than the sixth, the third, fourth and fifth subequal and longest, but not greatly exceeding the second. The best known species is Halcyon nigrocyanea Wallace, and I name this as type of the new genus DILAZULA." (Mathews 1918).    Var. Dialazula.

Search for more names on the Key to Scientific Names in Ornithology by James A. Jobling.
Recommended citation
Jobling, J. A. (2018). Key to Scientific Names in Ornithology. In: del Hoyo, J., Elliott, A., Sargatal, J., Christie, D.A. & de Juana, E. (eds.) (2018). Handbook of the Birds of the World Alive. Lynx Edicions, Barcelona. (retrieved from www.hbw.com on 15 December 2018).