occipital prominence, which, as \vc shall >ce. i> s«i nnu h hcUcr 

 marked in the loons. Finally, the supra-orbital -lanilular (loi)ri'-- 

 sions are hardly perceptible in these dabchicks. 



Grebes possess a hyoidean apparatus in some ropects peculiar. 

 It is well exemplified in Podilymbus, where we hnd the -iosso^ 

 hyal performed entirely in cartilage, and the first basibranc hial 

 represented by an expanded suboval disc of bone. At the 

 hinder margin of this the short second basibranchial, as a deli- 

 cate osseous rod, articulates in the middle line, while the long, 

 slender cerato-branchials, one on either hand, articulate close to 

 it. The epi-branchials are short and spiculiform. W'e find a 

 somewhat similarly fashioned first basibranchial in the tongue 

 of the kingfishers, but such a form of it is rare among birds. 



The sclerotal plates in the eye-balls of the Podicipoidea have 

 their usual ornithic characters, being of moderate size only, 

 squarish in form, and overlapping each other in the ordinary 

 manner. 



Birds of this superfamily vary, even for the genera, with 

 respect to the number of vertebrae in the spinal column, and the 

 corresponding vertebrae themselves vary much in form and 

 character. Species such as Colymbus JiollnvIH and Podilyjiibns 

 podiccps have 19 vertebrae in the cervical region of the spine, 

 the 19th bearing a pair of ribs that do not articulate by costal 

 ribs with the sternum. 



But .^chmophonis occidcutalis has 2 i vertebrae in the cervical 

 region, with the free ribs on the 21st as they occur on the 19th 

 in Podilymbus. This last mentioned species has the first four 

 dorsal vertebne fused into one piece, but the fifth one, standing 

 between this piece and the pelvis is free, and its ribs articulate 

 with the sternum by costal ribs. There is also a pair of pel- 

 vic ribs, the haemapophyses of which do not usually meet the 

 sternum. All have large epipleural appendages, save the last- 

 named ; they being even found on the cervical pair. They do 

 not fuse with rib borders. 



In ^chmophorus the dorsal vertebrae do not fuse, although 



