ON THE OSTEOLOGY AND SYSTEMATIC 

 POSITION OE THE PYGOPODES. 



In a series of papers contributed to Tlic Joitrnal of Anatomy 

 and Physiology ol London (i 889-1 890) appeared a number of 

 my drawings of the bones of pygopodine birds. Among these 

 the osteology of certain grebes and loons was illustrated, but the 

 material at hand then was meagre. Moreover, through an 

 oversight the plate illustrating the bones of the lower extremity 

 in the loons was omitted. The osteology of the pelvic limb in 

 a loon is in a way more deserving of our consideration than per- 

 haps other parts of the skeleton in those typical divers, and as I 

 had fortunately preserved the aforesaid plate, I take occasion to 

 publish it here. 



In an article entitled " Concerning some of the Eorms assumed 

 by the Patella in Birds" {Proc. U. S. Nat. Mus. \o\. vii, 1884, 

 pp. 324-331) I published two or three figures of the leg-bones 

 in loons and grebes, but the descriptive text-matter had reference 

 only to the morphology of the patella. 



In the pre.sent memoir all of my previous work has been 

 amplified and practically rewritten, while I have added my inves- 

 tigations upon the osteolog)- of the Pygopodes. 



In my classification of birds the Pygopodes appear in the 

 scheme as a suborder, thus : — 



Suborder: — PYCiOPODES. 



Slperfamilies: — 



Urinatoroidea. 



Eamilies: — 

 Podicipidi^;. 

 Urinatoridre. 



