434 On the Gallino-Gralline Group of Birds. 



truncated, so that the lateral processes extend considerably 

 beyond it. 



The Colymbo-Podicipes agree together in the following 

 characters : — 



1. They are heteroccelous in the articulation of their dorsal 

 vertebrae. 



2. The posterior processes of the ilia are approximated to 

 such an extent that the sacrum is almost hidden. 



8. The coracoids are furnished with subclavicular processes. 



4. They are holorhinal. 



5. The hallux is always present, but its basal phalanx is 

 shorter than that of the other toes. 



6. All the dorsal vertebrae in front of the anlcylosed sacral 

 vertebrae have ventral processes, 



7. The humerus is not pneumatic. 



8. They have no basipterygoid processes. 



9. The cnemial process of the tibia is remarkably developed. 

 The 2nd and 9th characters are equally diagnostic of the 



Colymbo-Podicipes. They differ from the Alcidse in the 

 1st, 2nd, 4th, and 9th characters. 



Impennes. 



The Penguins are regarded by many ornithologists as more 

 archaic than the Tinamous, but the arrangement of the 

 bones of the palate is so precisely that of a Bustard or a 

 Gull, that it is impossible to accept such a conclusion. It is 

 true that none of the feathers of the wing are differentiated 

 into quills, and that many of their osteological characters 

 are diagnostic, but it is not difficult to suggest a cause for 

 these facts. The quills of the wings of the Apteryx may be 

 slowly dying out by degradation by disuse, whilst those of the 

 Penguins may have rapidly disappeared by differentiation by 

 use for another purpose. It is much more difficult to suggest 

 the nearest allies of the Penguins : — 



1 . They are not heterocoelous in the articulation of their 

 dorsal vertebrse*. 



* The Penguins are more opistliocoelous than any other group in the 

 Order. The dorsal vertebrae are not only posteriorly concave, but they 

 are anteriorly convex, and in both cases the description applies as much 

 to the vertical as to the lateral section. 



