Alterapus

(syn. Rhaphidura Ϯ Sabine's Spine-tail Swift R. sabini) L. alter, altera  another  < comp. alius  other; genus Apus Scopoli, 1777, swift; "The third, C. sabini, is blue-black above, the upper tail-coverts white and long, the tail long and square with short projecting spines; the under-surface has the throat dark, the abdomen light: the feet are stout for the size of the bird in this group.  It does not correlate with the preceding, as the tail is more than one-third the length of the wing.  I therefore propose the new name ALTERAPUS with type Alterapus sabini (Gray)." (Mathews 1918) (see Neafrapus and Telacanthura).

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 14 December 2018).