710 CHIONIDID.B. 



Family V. CHIONIDID^E. 



Palate schizognathous. 



Nasals holorhinal. 



Basipterygoid processes and occipital foramina absent ; supra- 

 orbital impressions present. 



Bill with a complex rhamphotheca. 



Spinal feather-tract forked on the upper back. 



Feet not webbed; only a membrane between the base of the 

 inner and outer toe. 



Hind toe present. 



Tarsus reticulated on front and back. 



Nest in holes or behind rocks. 



Eggs one to three in number ; very similar to those of Oyster- 

 catchers, but thickly blotched with purple. 



Nestling covered with greyish down. 



Of. Seebohm, Class. B. p. 37 ; Stejneger, Standard Nat. Hist., 

 Birds, p. 92; Sharpe, Classif. B. p. 72; Shufeldt, Auk, x. pp. 158- 

 165. 



Key to the Genera. 



a. Face bare, and carunculated near the base 



of the bill ; a bare space below the eye . 1. Chionis, p. 710. 



b. Face bare in front of the eye, but not below 



it ; no caruncles on the base of the bill . 2. Chionabchus, p. 711. 



1. CHIONIS. 



Type. 



Chionis, Forster, Enchiridion Hist. Nat. p. 37 (1788) C. alba. 



Vaginalis, Gm. Syst. Nat. i. p. 705 (1788) C. alba. 



Coleorhamphus, Dumont, Diet. Set. Nat. x. p. 36 (1818) . . C. alba. 



Range. Confined to the extreme south of South America and 

 adjacent islands. 



1. Chionis alba. 



White Sheath-bill, Lath. Gen. Syn. iii. pt. 1, p. 268, pi. 89 (1785). 

 Vaginalis alba, Gm. Syst. Nat. i. p. 705 (1788). 

 Vaginalis chionis, Lath. Ind. Orn. ii. p. 774 (1790). 

 Coleoramphus nivalis, Dumont, Diet. Sri, Nat. x. p. 36 (1818). 

 Chionis vaginalis, Temm. PI. Col. v. pi. 509 (1830) ; id. Tabl. Meth. 



p. 100 (1836). 

 Chionis alba, Quoy fy Gaim. Toy. Uranie, p. 131, pi. 35 (1824) ; 



Gam. Sf Less. Voy. Corjuille, i. p. 724 (1826) ; Less. Man. d'Orn. 



ii. p. 341 (1828); id, Traite d'Orn. p. 521, pi. 109. fig. 2 (1831) ; 



Bluinv. Ann. Sci. Nat. vi. p. 97 (1836) ; Gould in Darwin's Voy. 



' Beagle; Birds, p. 118 (1841 : Falkland Is.) ; Gray, List Grail. 



Brit.Mus. p. 51 (1844: Straits of Magellan; Falkland Is.); id. 



Gen. B. iii. p. 522, pi. 135. fig. 3 (1845) ; Reichenb. Gall. tab. clxxix. 



figs. 1545-46 (1850) ; Bp. C. R. xliii. p. 420 (1856) ; Eyton, P. Z. S. 



1858, pp. 90, 100 ; Gould, P. Z. S. 1859, p 95, 1860, p. 386(Falk- 



