216 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [Feb. 20, 



Gastornis than in the Lamellirostres, does not appear to me to have 

 been more above the level of the trochlear surface than in the 

 Aptoi'tiis, Pezophaps, DlnorniSy or the Gallinacea. I believe, indeed, 

 that, if the prominent anterior parts of the condyles had been pre- 

 served in the Gastornis^ the appearance of the high position of the 

 bridge vrould have been much modified. The aspect, or plane, of the 

 lower outlet offers a useful character of comparison, and it appears 

 to me that it can be judged of in the Parisian fossil. The border of 

 the outlet is sufficiently entire to show that its upper and inner part 

 was most prominent, causing the outlet to look a little downwards as 

 well as forwards, or in some degree into the supra-condyloid cavity 

 below the canal. Now in the Lamellirostres, and in the Dio^nedea 

 and other Longipennate Palmipeds, the corresponding foramen looks 

 directly forwards : its plane is vertical, or, if inclined therefrom, it is 

 by the greater projection of the lower border, ^his foramen being 

 relatively lower in the Albatros than in the Swan, makes the Albatros 

 depart further from Gastornis. 



In the aspect of the lower outlet of the tendinous canal, the Gast- 

 ornis more resembles the known large wading and land birds and 

 the Dinornithidcje^ than it does any aquatic bird ; this character 

 appears not to have been taken into consideration in previous com- 

 parisons of the Gastornis. The fossa beneath the canal, bounded 

 below by the projecting border of the inter condyloid trochlear 

 surface, is a character which, though not precisely repeated, as to 

 the form, proportion, and position of that fossa, in any of the 

 Grallatores, finds its nearest correspondence in the usually larger 

 cavity at the corresponding part of the tibia in most birds of 

 that order : and I concur with MM. Hebert and Lartet in deeming 

 the fossa in question to indicate more directly an affinity of the 

 Gastornis to the Grallatorial order, than any other character 

 which the fossil bone presents. The anterior border of the trochlear 

 surface presents a similar projection in the Dinomis ; it bounds a 

 cavity below, which has its upper boundary in the ridge continued 

 transversely above the bridge, and into which the lower outlet of the 

 canal opens, as in the Bustard. The Swan, the Albatros, and other 

 Palmipeds show no trace of this anterior prominence of the trochlear 

 border; nor can any more trace be seen of a fossa below the ten- 

 dinous canal in the Albatros, than in the Swan or Goose. The 

 proportions of the tibia — its thickness, e. (/., in proportion to its 

 length — would plainly show, however, that the Parisian eocene bird 

 had more robust and shorter legs than in the typical waders ; and 

 probably was, as in other birds of like dimensions, better adapted 

 for terrestrial life. The result of the numei^ous comparisons which I 

 have made lead me entirely to concur in the final conclusion of 

 M. Hebert, viz. that the Gastornis belongs to a genus of birds 

 distinct from all previously known. 



