OF THE GALAPAGOS AECHIPELAGO. 485 



species, we have in these islands an instance of instability as regards size not often 

 met with in the class Aves. In some members, however, of the genus Oryzohorus, allied 

 to Guiraca, considerable variation is to be found in size, especially of the bill ; I refer 

 to 0. crassirostris, which has been divided into four or more so-called species, and to 

 0. torridus, which has not, so far as I am aware, been divided at all. 



Genus Cactornis. 



In 1843 Mr. Gould described a bird from Bow or Harp Island, one of the Low 

 archipelago, which he placed in the genus Cactornis, under the name C. inornatus. 

 The specimen, which was obtained by Mr. Hinds, and subsequently figured in the 

 'Zoology of the Voyage of the Sulphur,' at the time it was described formed part of 

 the collection of this Society, and afterwards passed into the British Museum. The 

 type appears to be a specimen of an immature bird, but it belongs to a genus distinct 

 from Cactornis, the tail being longer and somewhat forked, the bill more slender and 

 curved, and the mandible slightly projecting, and shows some affinity to Hemignathus. 

 G. R. Gray referred this bird to the Sandwich-Islands genus Loxops, calling it in his 

 ' Hand-list' (i. p. 114) Loxops inornata ; but it does not appear to be strictly congeneric 

 with that bird, the nostrils being exposed and not covered with densely set feathers. 

 The single specimen upon which Mr. Gould founded his Cactor^iis inornata is not suffi- 

 ciently mature for me to pronounce decidedly upon its position, but it appears to 

 belong to a distinct genus. Anyhow I feel justified in removing the bu-d from the 

 genus Cactornis, where Mr. Gould placed it. 



Omitting then C. inornata from Cactornis, this genus remains peculiar to the Gala- 

 pagos Islands. Its relationship to Geospiza is evident, the chief difference being the 

 great elongation of the bill compared with the stout bill of the latter genus. 



Cactoknis scandens. 



Cactornis scandens, Gould, P. Z. S. 1837, p. 7 ; Darwin, Zool. Voy. Beagle, iii. p. 104, t. xlii. ; Sol. 



& Salv. P. Z. S. 1870, p. 323; Sundev. P. Z. S. 1871, p. 124. 

 Tisserin des Gallapagoes, Neboux, Rev. Zool. 1840, p. 291. 

 Cactornis grimpeur, Prevost et Des Murs, Voy. Venus, Ois. p. 204. 



<3 nigerrimus, crissi plumis albo marginatis: rostro nigro flavo variegato, pedibus 

 corylino-nigris : long, tota 5-75, alse 2-85, caudse 1-75, tarsi 0-9, rostri a rictu 0-7. 



i juv. fuliginoso-niger, pileo obscuriore ; gula et pectoris plumis fusco marginatis ; 

 ventre imo et crisso sordide fuscis. 



? fusca, pileo obscuriore ; ventre imo et crisso multo pallidioribus : dorsi, guise et pec- 

 toris plumis pallido fusco marginatis: long, tota 5'25, alse 2'7, caudse 1'6, tarsi 0'83, 

 rostri a rictu 0'65. 



Hab. James Island {Darwin, Sundevall) ; Charles Island {Nehoux, Sundevall) ; Inde- 

 fatigable Island (Haiel). 



