CETPTUEI. 447 



corpore toto subtus albido, fasciis marginalibus brunneis maculatim notato. Long, tota circa 9-5, als 5-2. 

 (Descr. av. jun. typ. ex San Bias. Mus. Brit.) 



Hah. W. Mexico, San Bias (Belcher ^^).~l!i. Pacific, Japan 3, Kamtchatka^, Aleutian 

 Is. 3. 



This little Auk is an inhabitant of the coasts and islands of the North Pacific, being 

 found in Japan, Kamtchatka, and thence to the Aleutian Islands. In the British 

 Museum is a specimen said to have been obtained by Lieut, [afterwards Sir Edward] 

 Belcher off San Bias, in Western Mexico i. Grayson also mentioned his having seen 

 " Guillemots " at Isabel Island and off the Tres Marias group 7. Mr. Nelson, during 

 his visit to the latter islands, kept a sharp look-out for Auks or Guillemots, but 

 without result ^. 



Order CRYPrURI. 



The Tinamous are exclusively Neotropical. In external form they somewhat resemble 

 the Gallinae, but as regards internal structure and other features they differ in a marked 

 degree from the true Game-Birds. 



The Crypturi have, until recently, been considered a distinct order belonging to 

 the Carinatae, since they possess a keel to the sternum, but differing from all the 

 rest of the group in having a Struthious palate resembling that of the Ratitae. By 

 many naturalists, therefore, the Tinamous have been placed in the position of an 

 intermediate link between the Struthious and the Game Birds. 



Mr. Pycraft has recently made a study of thera, and considers that they are certainly 

 more nearly allied to the Struthious Birds than to the so-called Carinatae, the structure 

 of the palate being, in his opinion, of much greater significance than the presence or 

 absence of a keel to the sternum. He has proposed, therefore, that the Class Aves should 

 be divided into two great groups — the " Palaeognathae," consisting of the Struthious 

 Birds and the Tinamous, and the " Neognathse," to include all the remaining birds, this 

 second group being equivalent to the Carinatae without the Tinamous. 



According to him, the Palseognathse have the vomer and pterygoids directly connected 

 by squamous sutures, while the palatine bones are widely separated from one another 

 posteriorly, failing anteriorly to reach the palatine processes of the premaxilla. In the 

 Neognathse the vomer is often wanting, and when present it is supported by the 

 palatines, while the pterygoids take the form of short rods, articulating anteriorly with 

 the palatines by means of a joint. 



The palate of the Crypturi is decidedly of the Paleeognathous type, and is very similar 

 to that of Bhea. In the character of the nestling-down the Tinamous appear to be 

 unique. The aftershaft of the prepennse is as large as the main shaft ; preplumulas 

 are wanting ; the definitive feathers may have a moderately large after-shaft, or this 



