The bill of these birds was strong. The culmen was arched, and the maxilla overlapped the mandible at the base. The nostrils were covered by a membrane. The wings were large and the tail was moderate with pointed rectrices. The nearest relatives might have been from the genus Loxops.[2]
^Rothschild, Walter: The Avifauna of Laysan and the neighbouring islands with a complete history to date of the birds of the Hawaiian possession. London: R.H. Porter, 1893–1900.
H. Douglas Pratt, Jack Jeffrey: The Hawaiian Honeycreepers Oxford University Press, 2005 ISBN0-19-854653-X
Scott B Wilson & Arthur Humble Evans: Aves Hawaiienses: The Birds of the Sandwich Islands. 1890–99. R. H. Porter, London (Reprint: Ayer Publishing, 1974 ISBN0-405-05771-7)
Storrs L. Olson: History, Structure, Evolution, Behavior, Distribution, and Ecology of the Extinct Hawaiian Genus Ciridops (Fringillidae, Carduelini, Drepanidini). The Wilson Journal of Ornithology, December 2012, Vol. 124, No. 4, pp. 651–674 doi:10.1676/1559-4491-124.4.651