On Complete Fibulae in existing Birds. 361 



of the Missel-Thrush, Song-Thrush, and Blackbird are placed 

 together, followed by those of the Pied, Spotted, and Red- 

 breasted Flycatcher, the Common and Black Redstart, and 

 of two species of Corvus [C . frugilegus and C. capensis). 



Though the greater number of species of birds lay eggs 

 all of which are of tolerably uniform character, varying only 

 within narrow limits, there are some cases in which the eggs 

 laid by individuals of the same species present a remarkable 

 diversity. 



The examples at present shown of dissimilar eggs belong- 

 ing to one species are those of the Tree-Pipit, Tree- Sparrow, 

 Fan-tailed Warbler {Cisticola cisticola), and Guillemot, Of 

 the last-named six beautiful specimens have been selected 

 from the magnificent series lately presented to the Museum 

 by Mr. Seebohm, part of which is exhibited in the cabinet 

 of eggs in the British Gallery and part in the reserve 

 collection in the Bird Room. With these the series is 

 concluded. 



XXIX. — On cases of Com'pJete Fibulce in existing Birds. 

 By Dr. R. W. Shufeldt, C.M.Z.S. 



At the time Sir Richard Owen published his ' Comparative 

 Anatomy and Physiology of Vertebrates' in 1866, he was 

 not aware that the fibula in the legs of birds ever reached 

 the tarsus, and in giving a general definition for that bone 

 in the class Aves he wrote : — "The fibula is astyliform bone 

 ending in a point below at various distances down the tibia 

 in different birds " (vol. ii. p. 79) . This statement is the more 

 remarkable from the fact that that eminent authority, on the 

 opposite page (p. 78) of the work just quoted, figures the 

 pelvis and bones of the leg of a Loon (Colymbus) , and, as we 

 shall presently see, the fibula in that species is generally 

 complete in the adult. 



In 1872 Professor Huxley entertained the same view as 

 the one I have just cited from Owen, and in ' The Anatomy of 

 Vertebrated Animals,' which he published in that year, this 

 distinguished biologist states : — " The fibula of birds is 



SER. VI. VOL. VI. 2 c 



