24 W. P. PYCRAFT. 



Aptenodytes the width is nearly as great as the length. A feature which is somewhat 

 remarkable about the metapodials of the fossil forms is the fact that they are more 

 completely fused one with another than in living species. In the latter, as is well 

 known, the metatarsals are more or less divided by deep grooves along the anterior 

 aspect of the metatarsus, while these grooves are pierced in Aptenodytes by a pair of 

 intermetatarsal fenestrse, and in other genera by a single foramen between the inner 

 and median metatarsals. In the fossil forms only the inner groove is present, and this 

 is pierced near its upper end by a small foramen, except in Eosphseniscus, in which the 

 foramen is enlarged to form a long slit. 



Again, in the fossil genera the trochlese are set much wider apart than in living 

 genera, and this is especially true of the trochlea of Me. II., which diverges widely 

 from the trochlea of Me. III. 



This shortening of the metatarsals is in part due to the lessened use of the legs, 

 but the presence of the intermetatarsal grooves would appear to be a secondary, and not 

 a primitive, character, as has hitherto been supposed. Nevertheless, as we have shown 

 (p. 20), in the embryo the shafts of the metatarsals are more complete than in any 

 other living birds. 



Dr. Wyman, the author of the monograph on these fossils, attributes the shortening 

 of the metatarsals in living penguins to their plantigrade habits, but in this, of course, 

 he is in error, as these birds are nut plantigrade. 



All that can be gleaned from fossils, then, is that penguins have probably 

 descended from birds which possessed full powers of flight, and this probability 

 becomes converted into a certainty when the embryological evidence comes to be 

 examined. But the question of the precise affinities of this group must still be 

 regarded as an unsolved problem, the intense specialisation which these birds have 

 undergone obliterating much of the necessary evidence. 



It would seem, however, that we must regard the Steganopodes as representing 

 a common ancestral stock from which have descended the Sphenisci, Colymbi, and 

 Tubinares, on the one hand, and the Ciconise, Accipitres, and Anseres on the other. 

 And this conclusion is based on a consideration of a number of anatomical characters 

 into which there is no need to enter here. But among them I would specially mention 

 two, inasmuch as they have not hitherto been used in this connection. These are the 

 nature of the relations between the squamosal and parietal before their fusion, and the 

 nature of the palate at the same period. 



As I propose to deal elsewhere in detail with these characters, I will confine my 

 remarks thereon at present to those types immediately concerned with the subject in 

 hand that is to say, to the relationship of the penguins to the divers and petrels and 

 to the Steganopodes. 



At the stage in question all are schizognathous, and the penguins and divers, like 

 the Steganopodes, have a large squamosal, articulating with the hinder portion of the 

 postero-infero angle of the parietal, agreeing in this with the struthious types. The 



