THE VOYAGE OF THE BEAGLE 401 



built hovel, and therefore its transportation in a vessel is 

 not improbable : analogous facts have been observed by Dr. 

 Richardson in North America. 



Of land-birds I obtained twenty-six kinds, all peculiar to 

 the group and found nowhere else, with the exception of one 

 lark-like finch from North America (Dolichonyx oryzivorus), 

 which ranges on that continent as far north as 54 0 , and gen- 

 erally frequents marshes. The other twenty-five birds con- 

 sist, firstly, of a hawk, curiously intermediate in structure 

 between a buzzard and the American group of carrion-feed- 

 ing Polybori; and with these latter birds it agrees most 

 closely in every habit and even tone of voice. Secondly, 

 there are two owls, representing the short-eared and white 

 barn-owls of Europe. Thirdly, a wren, three tyrant-flycatch- 

 ers (two of them species of Pyrocephalus, one or both of 

 which would be ranked by some ornithologists as only varie- 

 ties), and a dove — all analogous to, but distinct from, Amer- 

 ican species. Fourthly, a swallow, which though differing 

 from the Progne purpurea of both Americas, only in being 

 rather duller colored, smaller, and slenderer, is considered 

 by Mr. Gould as specifically distinct. Fifthly, there are three 

 species of mocking thrush — a form highly characteristic of 

 America. The remaining land-birds form a most singular 

 group of finches, related to each other in the structure of 

 their beaks, short tails, form of body and plumage : there are 

 thirteen species, which Mr. Gould has divided into four sub- 

 groups. All these species are peculiar to this archipelago; 

 and so is the whole group, with the exception of one species 

 of the sub-group Cactornis, lately brought from Bow Island, 

 in the Low Archipelago. Of Cactornis, the two species may 

 be often seen climbing about the flowers of the great cactus- 

 trees; but all the other species of this group of finches, 

 mingled together in flocks, feed on the dry and sterile ground 

 of the lower districts. The males of all, or certainly of the 

 greater number, are jet black; and the females (with perhaps 

 one or two exceptions) are brown. The most curious fact is 

 the perfect gradation in the size of the beaks in the different 

 species of Geospiza, from one as large as that of a hawfinch 

 to that of a chaffinch, and (if Mr. Gould is right in includ- 

 ing his sub-group, Certhidea, in the main group) even to 



