432 MR. F. E. BEDDARD ON THE [JunC 3, 



The relationships of the bird from the point of view of the struc- 

 ture of the syrinx are somewhat doubtful. 



It is, in any case, very different from that of Pocliceps, of which 

 I propose to give a more detailed description in another paper. 



As to the Colymbida), I have in my possession a syrinx of Co- 

 lymhus sejitentriotmlis which agrees in all essentials with that of 



Fig. I. 



Syrinx of Pudica senegalensu, front view ; nat. size. 



Podica ; the only difference is that the bronchial semirings are 

 rather more numerous, and are hardly divided anteriorly by mem- 

 branous interspaces ; I do not mean to imply that they are fused, 

 but they are so close together as to leave only the merest chink 

 between adjacent rings. 



The resemblance then of Podica senegcdensis to Colymhus septen- 

 trionalis in respect of the syrinx is very close, but there are many 

 Rails which show an equally close resemblance to both, so that the 

 syrinx is unfortunately not very useful as a diagnostic character. 



§ 5. Osteology. 



Brandt [7, p. 199] remarks that Podoa and Podiceps agree closely 

 in the form of the skull, but that it is broader and more vaulted 

 posteriorly in Heliornis : it is clear from his figures (pi. xii. figs. 1, 2, 

 3) that Heliornis offers no marked points of difference from Podica. 

 In another section of the same paper (p. 155), Brandt comments 

 upon certain points of resemblance between Podoa and the Stegano- 

 podes ; there is, however, no detailed comparison of the skeleton in 

 any of these types. 



In spite of these alleged resemblances, Heliornis is placed with 

 Fulica into a separate Family (Podiceps being placed with Penguins 

 and Auks in another) of the six into which the Natatores are 

 divided. 



Giebel [6J has described, without figures, but in a more thorough 

 fashion, the osteology (and to a certain extent the soft parts also) 

 of Heliornis surinamensis, comparing it with the Grebes on the one 

 hand, and with various genera of Rails (Fulica, Gallimda, Porzana) 

 on the other. 



