Olson • THE EXTINCT HAWAIIAN GENUS CIRIDOPS 
659 
feathers” in “a specimen not quite adult” (AMNH 
459008) "agree with the plumage” of ihe green 
specimen, which is not irue. The most conspicuous 
remaining feathers in the transitional specimen are 
the brown inner secondaries and the brown midline 
of the belly, of which there is no trace in the green 
bird, whereas there is no trace of green, nor any 
gray in the breast, in the supposedly molting bird. 
Yet the green plumage continued to he regarded 
as ‘immature' (Pratt el al. 1987) or ’juvenile' (Pratt 
2002a. 2005). Pratt (2002a: 9) recognized “3 
distinct plumages ... with one in transition." but in 
the same paragraph he stated that the bird in red 
plumage with brown inner secondaries * ‘cannot be 
a transitional stage because it includes feathers not 
present in either” of the other known plumages. 
This was mooted by the discovery that at least parts 
of the juvenile plumage of the Hawaii Mamo 
(Drepanis paeifica) were of a decidedly brown 
color, similar to that retained in the 'transitional' 
plumage of Ciridops anna (Olson and Hume 2009). 
The plumage of the exquisite greenish specimen, 
which appears to be completely fresh and without 
wear, shows no evidence of the fluffiness, pointed 
rectrices. or other signs of a truly juvenile plumage 
(Olson and Hume 2009). making acceptance of it 
as being in the adult female plumage the only 
reasonable conclusion—one that was then accepted 
by Pratt (2010: 647, figure and legend). 
The only possible indication we have of 
breeding or molt cycles comes front the bird 
taken 2 February in ‘transitional' plumage 
(BMNH 1939.12.9.58). February is a time when 
neither Apapane (Himatione sanguined) nor liwi 
are undergoing any molt (Fancy and Ralph 1997. 
1998). Thus, if Ciridops were on a similar cycle, 
’transitional' male plumage with brown feathers 
may not have been evanescent and possibly lasted 
a full molt cycle so that ii may have taken 2 years 
for males to attain the definitive plumage. This 
gains support from half of known male specimens 
being in non-definitive plumage. If Ciridops anna 
were a highly territorial species, there would have 
been a decided evolutionary advantage for fully 
adult territorial males to be able to distinguish 
females and non-territorial subadult males from 
threatening conspeeific invaders. 
INTERNAL MORPHOLOGY OF CIRIDOPS 
Tongue Morphology 
The tongue of Ciridops anna was first illus¬ 
trated by Rothschild (1900: plate 83. figs. 55, 
55a—natural size and enlarged) who made no 
further comment on it other than that it indicated 
that Ciridops belonged with the “Drepanidae” 
rather than the Fringillidae (Rothschild 1900: 
181). Amadon (1950: 222) reproduced the en¬ 
larged view along with the tongues of other 
drepanidines. Carlquisl (1965: 125) constructed a 
’tongue phylogeny' by superimposing illustrations 
from Amadon (1950) on Amadou’s tree of 
drepanidine relationships, but many of the tongues 
were redrawn in different views from the originals 
and are probably in part fanciful. Bock (1972: 76) 
illustrated the tongue in several views in great 
detail and found the structure of the corneous 
tongue in Ciridops to be similar to that in other 
drepanidines with tubular tongues but that it 
“differs from that of ‘coerebidsL.. in that no 
eoerebid' possesses laciniae along the upturned 
lateral edges of the corneous tongue.” The tongue 
of Ciridops was fringed and tubular as typical of 
the presumably nectarivorous tongues of its close 
relatives but was shorter in accordance with the 
short length of ihe bill. 
Osteology of Ciridops anna 
The skeletal morphology of Ciridops was 
investigated using fossil material and also the 
skull and mandible, humerus, tibiotarsus, and 
tarsometatarsus removed (Olson et al. 1987) from 
the remaining Harvard study skin of C. anna 
(MCZ 10995), and the pelvis and femur from 
BMNH 1939.12.9.58. 
Cranial Osteology .—The skull and mandible of 
Ciridops anna are decidedly not finchlike "but 
are shortened versions of the thin weak structures 
found in the nectarivorous genera Himatione, 
Palmeria . Vestiariu , and Drepanis" (James and 
Olson 1991: 73). Four characters were identified 
that confirmed the placement of Ciridops with 
that same ’red and black' group of drepanidines 
(Division I of Perkins 1903), from which 
Ciridops was distinguished "by its much shorter 
bill, constricted dorsal nasal bar. upturned retro- 
articular process of the mandible, deep mandib¬ 
ular ramus (middle part), and enlarged mandibular 
foramen” (James and Olson 1991: 73). 
The skull and mandible of Ciridops are 
contrasted (Figs. 2, 3) with those of a typical 
nectanvore. the Apapane, and the Poo-uli. which, 
although not typical of the truly finch-like 
drepanidines such as Telespiza, is a basal taxon 
within the radiation (Lerner et al. 2011) and 
