UB-ORDER 



GAVIAE. 



In the table, on page 594, taken from Bonaparte's system of 1853, the Gaviae are made 

 to consist of the Tolipalmi and Longipennes ; the Anseres of Lamellirostres, Urinatores, and 

 Ptilopteri. Subsequently the Urinatores, or Bracliypteri, were removed by that author to the 

 Gaviae, and the Ptilopteri, or Impennes, raised to the rank of a separate order. How far this 

 modified arrangement agrees better with the author's primary idea of AUrices and Praecoces I 

 am unable to speak ; if some of the Bracliypteri are known to rear their young in nests, the 

 majoiity are supposed te conduct them to the water as soon as hatched. Be the circumstances, 

 in this respect, as they may, the later arrangement of the orders and sub-orders seems the more 

 natural, and I therefore adopt it in the present case. 



As already stated, the chief characteristic of the Gaviae is to be found in the entire absence 

 of lamellae within the edges of the bill. The wings are either conspicuously lengthened, as in 

 the Longipennes ; or they are quite short, the hinder toe connected to the anterior by a mem- 

 brane, (Totipalmi,') or free, {Urinatores.) In all, the toes are well webbed, although the web is 

 sometimes split. The young in most Longipennes, at least, are born helpless, and reared for a 

 certain time in the nests. 



The sub-order was originally divided by Bonaparte, as stated, into two tribes, Totipalmi and 

 Longipennes, to which he subsequently added the Urinatores. Their characters are as follows : 



A. Totipalmi. — Hind toe connected with the inner by a membrane^ and more or less lateral 

 or anterior. Bill generally longer than the head, and usually with a sharp curved nail at the 

 end ; sometimes without it. Nasal aperture an elongated narrow slit ; sometimes scarcely 

 visible. Face and throat usually somewhat naked. 



Pelecanidae. — Upper jaw with a hooked, decurved, and acute nail at the tip. Edges of 

 the bill even, without serrations. Throat naked, with an extensible pouch. 

 Pelecaninae. — Tarsus and throat naked. Tail broad, rounded. 

 Tachypetinae. — Tarsus feathered. Wings and tail excessively lengthened ; the 

 latter deeply forked. 

 Plotidae. — Bill straight, notched or serrated on the edges, with a slightly curved nail, 



or none. Face and chin partly naked. Tail rounded, or cuneate ;' rather long. 

 Phaetonidae. — Bill without nail, slightly curved ; edges scarcely serrated. Head entirely 

 feathered. Tail with the middle feathers excessively lengthened. 



B. Longipennes. — Hind toe disconnected from the lateral, small; the anterior toes webbed to 

 the claws. Wings lengthened, acute ; tlie first primary generally as long as the second. Bill 

 ■without serrations. No naked spaces about the head. 



