EEPOET ON THE SPHENISCID.95. 



43 



" ambiens " muscle. Immediately below this groove, ou the outer side of the bone, is 

 a well-marked tubercle, to which the tendon of the biceps is attached. 



The fibula is closely attached to the tibia by its head and by the upper and lower 

 thirds of its shaft, but is separated from that bone opposite its middle third by an 

 interval through which arterial branches pass from the back to the front of the limb. 



In all the Penguins examined the fibula presents the same form, but differs somewhat 

 in length relatively to the tibia in the various genera. In Pygosceles and Eudyptes the 

 lower end of the fibula reaches the base of the external condyle of the lower end of the 

 tibia. In Aptenodytes it is rather shorter, while in Spheniscvs the fibula is shorter than 

 in any other genus, its lower end falling considerably short of the external condyle of the 

 tibia (in Spheniscus demersus by half an inch). 



The table shows the length of the fibula of different species in inches : — 



Eudypdes chrysocome, from Tristan, 



Eudyptes chrysocome, from the Falklands, 



Eudypjtes chrysocome, from Kerguelen, 



Eudyptes chrysolopli us, 



Spheniscus demersus, 



Spheniscus magellanicus, 



Spheniscus meiuliculus, 



Spheniscus minor, 



Pygosceles tceniatus, 



Aptenodytes longirostris, 



H 



3| 

 3| 

 3f 



3i 

 3 



5i 



