216 



1116. The tarso-metatarsal bone of a Bustard (Otis tar da, Linn.). 



The two foramina near the proximal end lead to canals which indicate the primitive 

 distinction of the three constituent metatarsals : a canal near the distal end, traversing the 

 bone from before backwards, is likewise another trace ; the three distinct trochlear distal 

 ends most clearly manifesting the composite character of the bone. The calcaneal process 

 is connate with the back part of the tarsal portion of the bone. 



Hunterian. 



1117. The distal end of the tibia and bones of the right foot of a Penguin (Apteno- 



dytes patachonica) . 

 \ 

 The cut surface of the tibia shows the solidity of the bone characteristic of this strictly 



aquatic and wingless bird. The groove of the extensor tendons has been converted into a 

 canal by an osseous bridge, developed in part of the annular ligament in this and many other 

 birds. The primitive distinctness of the three short metatarssls is well shown by two wide 

 longitudinal grooves, leading to two antero-posterior perforations, as well as by the distinct 

 distal articular ends. The difference in the number of the phalanges of each of the toes, 

 and its progressive increase from the inner or tibial to the outer side of the foot, is here 

 seen. The toe with three phalanges answers to the second in the pentadactyle foot ; the 

 next, with four phalanges, to the third toe, or 'medius'; the one with five phalanges to the 

 fourth toe ; the fifth or little-toe is wanting in all birds ; a rudiment of the first or hallux 

 exists in the Aptenodytes, and is attached to the tibial side of the anchylosed metatarsal of 

 the second toe. 



Hunterian. 



Order NATATORES. 



Family Pinnipennatce. Divers. 



Genus Aptenodytes (Penguins)*. 



1118. The skeleton of the Antarctic Penguin (Aptenodytes antarcticd). 



The number of vertebrse between the skull and sacrum is 21, the last seven of which sup- 

 port moveable ribs, an eighth pair of ribs being attached to the first sacral vertebra, and the 

 rudiment of a ninth pair being connected with each sacral rib. The last six dorsal ribs arc 

 attached to the sternum by bony hsemapophyses, and, together with the first pair, have bony 

 appendages articulated to them. The ribs of the first pair are free, without hsemapophyses : 



* No species of this genus is known to exist north of the Equator. 



