STRUtHIOUS BIRDS. 



f 



[Right-hand side of entrance 

 Subclass I. SAURUR-ffi. to Gallery. Restoration and 



framed cast of fossil remains.] 



Fossil remains, hitherto only found in the lithographic slate of 

 Solenhofen, in Bavaria, indicate that birds existed in the Upper Jurassic 

 geological age, differing in certain points from those now existing. The 

 jaws were armed with teeth, and the three digits of the fore-limb were 

 furnished with claws. The tail consisted of a series of elongated 

 vertebrae, gradually tapering to the extremity, each vertebra bearing a 

 pair of well-developed feathers. As the skeleton of the tail rather 

 resembled that of a Reptile than that of a modern Bird, the name 

 Saurura, signifying ' Lizard-tailed,^ has been applied to the group. 



The best known representative of this subclass is the Archceopteryx 

 lithographica (1). A cast of the fossil remains of this remarkable form 

 is exhibited at the entrance to the Bird Gallery. For full particulars 

 the reader is referred to the ninth edition of the " Guide to the Fossil 

 Mammals and Birds/' pp. 93-95 (1909). 



Subclass II. NEORNITHES. 



This Subclass includes all the remaining forms, both recent and 

 fossil, included in the Class Aves, and may be divided into two sections : 

 A. Raiiia, and B. Carinatce. The first contains the Struthious Birds 

 and the Tinamous, and the second all the existing Birds not included 

 in the previous division. 



Section A. RATITiE. 

 Struthious Birds and Tinamous. 



In this Subclass are included all the great flightless species of the 

 Ostrich-tribe commonly known as the Struthious Birds, as well as the 

 Tinamous. The name Ratitse is derived from the raft-like breast-bone 

 of the former, which is devoid of a keel for the attachment of the pectoral 

 muscles. As these muscles gradually ceased to be used they became 

 degenerate, the keel for their attachment disappeared, and, as a result, 

 the birds lost the power of flight. Though at the present period 

 represented by comparatively few members, which are confined to 

 Africa, the Papuan group of islands, Australia, New Zealand, and 

 South America, the " Ratites " were formerly much more numerous in 

 species, and ranged over parts of the earth M^here they have long since 

 ceased to exist. A number of fossil forms are known. 



The Ratitse may be distinguished from all other birds by the bones 

 oC the palate, the pterygoid never forming a jointed articulation with 



