PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 327 



thes page 93). I fail to find any sucli foramen in the patella of the 

 specimen of Sula before me, although it has a shallow, obliqne groove 

 across its anterior face that seems to correspond with the one described 

 when speaking of the patella of the Penguin. One of the most inter- 

 esting and at the same time one of the most familiar to us is the ar- 

 rangement of these bones in some of the divers. To illustrate the con- 

 dition of things as they are in these birds, I have chosen and drawn the 



FIG. 2.-C. Femur and leg^ones of Corvus^er^^ §^^ ^"^^'A' iS'llnl^tTmr^us 

 normal position. f^^O; ^33, Collection in Army M^^^^^ ^^^ ^^^^^^ .^ their norma pp- 



serrator, shoeing the two ^-l^.^entery patel a. surrounaea D>^n^^^ f,assano,^ith femur and patella 



sition. (No. 16626, Smithsonian Collection) Ji. »am6 bones i™™ j Collection.) All the figures 

 thrown somewhat out of their normal P^'S'tion <^''„4<L^^^%Xr'^r tibia ; Fb, fibula, and P, patella, 

 are life-size, chosen from the right limb, and F sigmties temur , ±, uui<i, 

 throughout. Drawings by the author. 



bones of the leg in Pordieps cornutum (Fig. 3), giving two difierent 

 views. Probably no better example exists in all nature showing the 

 coexistence of a patella with a prolonged cnemial crest of the tibia 

 than we fine in Fodiceps. When in position it is closely applied by its | 

 anterior surface to the posterior surface of the greatly produced rotular 

 process already alluded to, extending somewhat above it, which exten- 

 sion in some specimens is bent slightly forward. 



This strongly suggests the idea that the olecranon of the ulna can in 

 noways be considered as being homologous with the patella, but only 

 with the rotular process of the tibia; indeed, in each case I must agree 

 with Coues in this matter, and regard these processes as mere exten- 

 sions of the shaft of the bones in question. (The Medical Record, 18/0, 

 p 194 ) In the case of Cohjmhus a positive requirement is met, and 

 that is to aflbrd additional surface for the insertion of the extensores 

 cruris, as well as affording greater leverage in the play of the limb. 



