500 HARRY GOYIER SEELEY ON THE 



would be the palatal surface. It is 2^ inches long, f inch wide in 

 front, and ly 1 ^- inch wide behind. The sides are smooth, finely 

 wrinkled, concaYe in length, conYex from above downward, with 

 small oblique vascular foramina near the border, which may be 

 alveolar ; there are also foramina on the middle of the side. Supe- 

 riorly the sides converge in a rounded ridge. It is T | inch deep in 

 front, and 1J inch deep behind. The great difficulty in the way of 

 regarding it as an Avian prem axillary is that, although it widens 

 behind somewhat rapidly, it shows no indication of a nasal groove 

 or cavity, though the Diver has no lateral groove on the beak. And 

 the recent discovery of Toothless Pterodactyles by Prof. Marsh in 

 the Cretaceous beds of America lends some support to my original 

 determination of the bone as Ornithosaurian. 



I would suggest that since the birds from the American Grecnsand 

 having teeth in their jaws show affinities with Coh/mbus, it is pro- 

 bable that Enaliomis, which has vertebra? resembling those of 

 Iclitliyornis in biconcave character, may also have had teeth in its 

 jaws. 



The Vertebral Column. 



Cervical vertebrae have rarely been found. Some twelve years ago 

 I detected what seemed to be a lower cervical in the collection of 

 W. Reed, Esq., E.Gr.S., but have not noticed any other specimens. 

 The vertebras most commonly found, and best known, are dorsal. 

 One in Mr. Eeed's collection has the visceral surface of the centrum 

 terminated by a sharp ridge, while nil the other specimens (including 

 four in the TVoodwardian Museum) have this surface convex. Mr. 

 Reed's two vertebra probably belong to the two species of birds to 

 which I refer the bulk of the remains, though this could only be defi- 

 nitively determined by a careful study of the somewhat abraded fossils. 

 Of the sacrum, the Woodwardian Museum has three important speci- 

 mens demonstrating the essential points of structure ; another frag- 

 ment of the postfemoral part of a sacrum has been obtained by James 

 Carter, Esq., of Cambridge. These specimens are all from the an- 

 terior and middle regions of the sacrum, and are such as might all 

 belong to one genus. The Woodwardian Museum also contains two 

 other vertebrae, apparently proccelous, which I am disposed to re- 

 gard as bird-bones, and refer to the tail. As they have no trans- 

 verse processes, they are probably elements which, in existing birds, 

 are united in the ploughshare bone. 



Lower Cervical Vertebra. (PI. XXVI. figs. 5, 6.) 



The centrum measures f inch in width over the anterior zygapo- 

 physcs ; the length of the centrum is T 7 ¥ of an inch ; the width of 

 the centrum in front is nearly j\ inch, where the anterior articu- 

 lation is concave from side to side, convex from above downward ; 

 it is more than T \ inch deep ; and at its base a short tubercle is 

 developed. The base is concave, long, narrow, flattened, and con- 

 cave from side to side. It is margined by sharp concave borders. 



