ZEUGLODON OSIEIS. 239 



The dimensions (in centimetres) of the teeth (or their alveoli) are : — 



Length. "Width. Height. 



i. 1 (alveolus only) 2-2 



i.2 „ 2-5 1-6 



1.3 „ 2-5 1-5 



c. 1 „ 2-9 1-5 



pm.l- „ 2-9 1-4 



pm.2 3-8 1-9 3-6 



pm. 3 (alveoli only) 5 



pmA 5-2 2-5 5 



m. 1 3 2-5 



m. 2 2-8 2-5 3-9 



m. 3 3-2 2-5 3-5 



Some of the above meiisurements of the teeth are probably somewhat in excess of the 

 truth, owing to the presence of a coating of gypsum. 



M. 9264. Plaster cast of the above specimen. Made in the British Museum. 



The following specimens are referred provisionally to this species : — 



C. 10055. Five caudal vertebrae. In these the epiphj'ses are fused to the centrum, which measures 

 in length 7*5 cm., in width 7"7 cm., in height 7 cm. The neural arch, enclosing a very 

 small neural canal, is situated on the anterior half of the centrum. There are broad 

 transverse processes, the bases of which are perforated by a foramen. There seem to 

 have been no vascular foramina on the ventral face of the centrum, which bears at its 

 hinder end a pair of facets for the chevrons. 



C. 10051. Six associated vertebrae, similar in general form to the last, but belonging to a much smaller 

 animal, the length of the centrum in the largest of these specimens being only 

 about 5 cm. 



C. 10309. Four posterior lumbar and anterior caudal vertebrae, closely similar to the specimens figured 

 by Dames {loc, cit. 1894, pis. xxxv., xxxvi.) and referred by him to Z. osiris. The ends of 

 the centrum are slightly concave, the epiphyses being fused. The neural arch has a 

 pedicle extending over three-fourths of the length of the centrum. The transverse 

 processes are large and directed downwards and backwards ; in the caudal the base of 

 the process is perforated. In the lumbars the ventral face of the centrum is concave 

 or only very slightly convex from side to side ; in the middle are two large vascular 

 foramina separated by a narrow bar of bone ; there is also a foramen (or a pair) in the 

 floor of the neural canal. In the caudal vertebra there seem to have been large facets 

 for the chevrons. These specimens are from the Birket-el-Qurun beds. The dimensions 

 (in centimetres) of the centra of these vertebrae are : — 



lumbar. 



Length 6-7 



Width 8-5 



Height 7-5 



b. 



6'8 app. 

 8-2 

 7-4 



Caudal. 



c. 



6-7 

 8 

 7 app. 



