1905.] 



DINOSAUR CETIOSAURUS LEEDST. 



235 



Sacrum. 



The sacrum is known only by the neural spines (text-fig. 39, 

 p. 233), of which it seems possible to identify four. Each spine 

 is strengthened on its lateral face by an irregular vertical i-idge 

 of bone, and is sharply truncated at its upper end. Tliree are 

 fused together into one plate and (from analogy with a corre- 

 sponding arrangement in D'qylodocus) may be regarded as belonging 

 to the three anterior sacral vertebrae. The fourth spine is placed 

 separately just behind the composite plate. 



Caudal Vertebrce. 



Of the four anterior caudal vertebra? preserved in the new spe- 

 cimen, shown in text-fig. 39, p. 233, the two foremost are too much 



Text-fiff. 41. 



Cetiosaurus leedsi. — Anterior caudal vertebra ; anterior and (A) left lateral aspects. 

 as., prezygapopliyscs ; L, broken lateral flange of bone ; tr., transverse process, 

 incomplete. About ^ nat. size. 



broken to display many of their characters. As mounted, indeed, 

 the neural spines are hypothetically ascribed to the centra beneath 

 them. The centra are very short and slightly broader than deep, 

 each bearing traces of transverse processes placed rather low on 



