2362 



REPTILES 



from front to back, and have concave surfaces both in front and behind for mutual 

 articulation. In marked contrast to this type is the neck vertebra of a Dinosaur, 

 where the anterior end of the body of each vertebra forms a convex knob (b), 



I.EFT SIDE OP THE SKTJI.I, OF A BEAKED FLYING DRAGON. 

 (One-sixth natural size.) 



a. vacuity in front of the eye; b. socket of the eye; c. occipital spine; d. angle of lower jaw; e. extremity of up- 

 per, and i of lower jaw; q. articulation of the skull proper with the lower jaw; s. point where the two branches of 

 the lower jaw diverge. After Marsh. 



received into a cup at the posterior end of the vertebra in advance.* In other 

 instances, as in the existing crocodiles and lizards, an arrangement precisely the 

 reverse of the last is present, that is to say, the ball is at the hinder end, and the 



cup at the front of the body of the vertebra. 

 In a few lizards and in all snakes the verte- 

 brae are further complicated by the develop- 



I.EFT SIDE VIEW OF A NECK VERTEBRA 



OF A DINOSAUR. 

 b. anterior ball. After Marsh. 



i- 



SIDE AND FRONT VIEWS OF THE BODY OF A 

 VERTEBRA OF A FISH UZARD. 

 a, b. attachment of ribs. 



ment of additional articular facets, taking the form of wedge-like projections from 



one vertebra, which are received into cavern-like excavations in the adjacent one. 



Omitting mention of certain features connected with their osteology, it may be 



observed that among those reptiles with four or five toes to each foot, while a few, 



* It should be mentioned that In this figure only the portion of which b is the extremity corresponds with the 

 whole of the specimen represented in the other figure on the same line. 



