266 Mous. A. Milne-Edwards on the 



the depressions hollowed out on the lateral surfaces of the tro- 

 chlea shows that the toes must have been very firmly attached 

 to the bone of the foot. The articular facet of the hind toe is 

 large and depressed, so that the lower orifice, through which 

 passes the tendon of the adductor muscle of the outer toe, is 

 large ; but it is only continued on the body of the bone by a 

 furrow, which is scarcely visible. 



The characters I have just described show in the clearest 

 manner that the bone in question cannot come from a bird of 

 prey, nor from one of the Passeres, nor from a web-footed bird. 

 It must have belonged to a walking bird ; and, from its general 

 form, as well as from many of its characters, it resembles that 

 of the Gallinacece. Still it is impossible to refer it to this last 

 group. In fact, among all the Gallinacea, without exception, 

 the flexor muscle of the hallux is attached to a deeply hollowed 

 surface on the inner posterior side of the heel, and is bounded 

 by very prominent ridges. This character, as I have already 

 said, is wanting in the tarso-metatarsus recovered from the 

 Mare aux Songes. The digital trochlese of the Gallinacea are 

 always much shortei', and that of the inner toe is prolonged a 

 little lower than in this last. Lastly I will add that in nearly 

 all the birds of this group, even in many that are deprived of 

 spurs, there is always a ridge or a bony stay uniting the inner 

 posterior ridge of the bone to the heel. 



If we compare the fossil metatarsus with that of the Waders, we 

 see that its relative proportions, as well as its anatomical peculia- 

 rities, remove it from that of the Ciconiidce, Gruid(S, Ardeida, Sco- 

 lopacidce and Charadriidce, and Bustards. But we find in it great 

 analogies with that of certain members of the family Rallidce, 

 although it differs much from the normal form of that group. 

 In these birds, indeed, the digital trochlese ai-e very close to each 

 other, and the lower extremity is consequently narrow, whereas 

 in our fossil the contrary arrangement is observable. The foot 

 of Porphyrio is distinguished, not only by this character, but . 

 also by the depth of the anterior metatarsal furrow, and by that 

 of the insertional surface of the flexor muscle of the hallux. 

 This peculiarity is not to be found in the Rails, the Water-hens, 

 the Jacanas, or Tribomjx ; but the bone of the tarso-metatarsus 



