Sijstematic Position of the Sheath-bills. 137 



(3) Femur CJiionarchits (S^ mm. C7iioiiis -'m mm. 



(4) Tarso-iuetatarsus „ 49 luui. ,, 4-) iimi. 

 {■')) Middle toe ,, 48 mm. ,, 39 mm. 

 (0) Skull: — 



[a) Irom occipital protuberance to tip of premaxill.t — 



(1) Chiunarchus^' minor " 70 mm. 



(2) CMonis alba 6o mm. 



{}>) Transverse diameter from tips of post-orbital processes identical 



in the two forms. 

 ((•) From tip of preniaxillas to end of nasal processes of tlse same. 



(1 ) (Jliionarchus " minor " :',~yb nun. 



(2) Chionis alba 30 mm. 



From wliicli data it will be noticed that, far from Chion- 

 archus "' minor " being the smaller bird, it is, in fact, 

 actually larger. It seems therefore probable, if not certain, 

 that Hartlaub's C. minor did not hail from Kergueleu Island, 

 and the deduction is that it must have come from either 

 Marion Island or from the Crozets. (I have not seen a 

 skin from Heard Island = C. nascicornis of Reichenow.J 

 Both the Marion Island and Crozet forms are very obviously 

 smaller than C. " minor " from Kerguelen. It is also 

 obvious that further remarks would be useless until the 

 type of C. minor in tiie Leyden Museum has been examined, 

 w hich at the present time is impossible. 



[b) Chionarchus marionensis (Heichenow), Deutsche 



Siid-Polar Exp. i. 1908, p. 566. 

 Type-locality — Marion Island (Prince Edward 

 Island, Southern Indian Oceauj. 



(c) Chionarchus nascicornis (Reichenow), Oruith. 



Monatsb. xii. 1904, p. 47. 

 Type-locality — Heard Island (Southern Indian 

 Ocean). 



{d) Chionarchus crozettensis (Sharpe), Bull. B.O.C. 

 V. 1896, p. xliv. 

 Type-locality — Crozet Islands (Southern Indiau 



Ocean). 

 Type in Biit. Mus. 



