3. CACTORNIS. 19 



2. Cactornis scandens. 



Cactornis scaniieus, Gmdd, P. Z. S. 1837, p. 7 ; Darwin, Zool. Voy. 

 '■Beagle,'' Birds, p. 104, pi. xlii. (1841) ; Gray, Gen. B. ii. p. 359 

 (1844); Bp. Comp. i. p. 542 (1850) ; Scl. $ Salt. P. Z. -S'. 1870, 

 p. 323 j Gray, llaad-l. B. ii. p. 8'J, no. 7307 (1870); Sundec. 

 P. Z. S. 1871, p. 124; Scl. §■ Xah: Nomsncl. Av. Xeotr. p. 21) 

 (1873); Salvin, Trans. Z. S. ix. p. 485 (1S70). 



Tisserin ties Gallapagoes, Neboux, jRev. Zool. 1*40, p. 291. 



Cactoruis griinpeur, Prevost el Des Mars, Voy. V6nus. Ois. v. p 204 

 (1855). 



Adult male (type of species). Similar to C. assimilis, but smaller. 

 Colour entirely black. Total length 4 - S inches, culuien 0*7, wing 

 2-65. tail 1-6, tarsus - S. 



Adult female. Differs from the male in the same way as the 

 female of C. assimilis. Total length 5 inches, culmen 0-05 win* 

 2-85, tail 1-6. 



Young nudes resemble the adult females, but are generally darker 

 and more sooty, the throat especially being sooty black. 



Only one male in the series from Indefatigable Island has the bill 

 entirely black, and this specimen has the base of the inaudible horny 

 yellow. The plumage is deep black, except on the lower back and 

 rump, where there are still some greyish tips to the feathers. Tho 

 under tail-coverts are also broadly margined with ashy white. 



Another adult male has the bill reddish horn-colour, paler on 

 the under mandible and black near the nostrils, as if the bill were 

 gradually turning black. This specimen has the black plumage 

 more sooty and obscured with ashy margins to the feathers on the 

 back and breast, the abdomen being whitish. 



It is difficult to determine whether these ashy edges to tho black 

 plumages of the males are the evidence of immaturity or of a seasonal 

 plumage. It is, however, quite evident that the males take a con- 

 siderable time before they attain the adult dress, and the way in 

 which a blacker bill accompanies the fully black plumago seems to 

 show that it is a sign of the breeding-season. 



The.adult males from Indefatigable measure: — Culmen 0-75-0-85, 

 wing 2-9-3, tarsus 0-8-0-85. 



The adult females from the same island measure : — Culmeu - 75- 

 0-8, wing 2-7-2-8, tarsus 0-8-0-85. 



The young males from the same island measure : — Culmen 0-75- 

 0-8, wing 2-75-2 8, tarsus 0-8-0-85. 



An adult male from Bindloe Island measures : — Culmen - 8, wing 

 2-9, tarsus 0-9. It will be noticed that the tarsus is longer than in 

 any other specimen in the series ; but whether this slight difference 

 would be borne out by a larger number of specimens from this 

 island remains a question. 



The variation in size in this species is somewhat remarkable, and 

 the typical specimens from James Island are decidedly smaller than 

 those from Indefatigable. 



Hob. James, Indefatigable, and Bindloe Islands in the Galapagos 

 Archipelago. 



c2 



