450 



Family VIII. XENICID^. 



Our knowledge that the two peculiar forms of New Zealand — 

 Acanihidositta and Xenicus, are non-Oscinine is entirely due to the 

 researches of Forhes, who investigated their anatomical structure 

 in 1882*. Forbes showed that the syrinx in these two genera is 



A. Syrinx of Xenieus lovqipes, front view. B. Hind view, in Lateral 

 tracheal muscle. (P. Z. S. 1882, p. 570.) 



mesomyodian, and that the presence of a tenth external primary 

 and the nou-bilaminate tarsus are further indications of their non- 

 Osciuine affinities. In other points the Xenitidee, as Forbes named 

 the family, conform to the general Passerine type. There is no 

 trace of a plantar vinculum, the arrangement of the tensor patagii 

 brevis is Passerine, the main artery of the leg is the sciatic, and the 

 sternum has a single pair of posterior notches and a bifid ma- 

 nubrium. 



On the whole the Xenicidce must be held to be more nearly allied 

 to the Pittidee than to any other Passerine form yet known. But 

 they have only 10 rectrices instead of 12 — the normal Passerine 

 number, and the scutellation of the tarsus is different. 



The two known genera of Xenicidee are entirely confined to New 

 Zealand, no Australian form with similar structure having been yet 

 met with, although it is quite possible that such may be hereafter 

 discovered 



My account of these three birds is freely adopted from Sir W. L t 

 Puller's new edition of his ' Birds of New Zealand,' by the kind 

 permission of the author. 



Key to the Genera. 



Bill very thin, compressed, pointed; 

 tarsi thin, about twice the length of 

 the hind toe 



Bill stouter, more broadened at the 

 base ; tarsi stouter, longer, more than 

 twice the length of the hind toe . . 



1. ACANTHIDOSITTA, p. 451. 



2. Xenicus, p. 452. 



See P. Z. S. 1882, p. 569. 



