372 PEOF. ST. GEOEGKE MIVAET ON THE 



twenty-fifth vertebrae may be opisthoccelous ; a median snbvertebral process may be 

 formed, of bent-down lateral hypapophyses conjoined, as in Plotus; lateral acetabular 

 fossa subtriangular or quadrate, but never enormous in size ; supraacetabular fossa 

 present or absent; always a marked interval between lumbar and caudal vertebrae 

 through non-development of parapophyses ; sacral vertebrae distinct or not so. Pelvis 

 including from fifteen to seventeen vertebrae ; ilia not meeting at an acute angle ; no 

 conspicuous ilio-pectineal processes ; ilia not flattened against the postacetabular verte- 

 bree ; acetabula, preaxiad to the antero-posterior middle of the pelvis ; ischia and ilia 

 largely united postaxially; pelvis more vertically extended behind than in front of 

 acetabula; postacetabular part of pelvis broader transversely than the preacetabular 

 part; ilio-caudal spine present or absent; preacetabular parts of ilia meeting in a 

 median dorsal ridge; dorsum of postacetabular part of ilium not high, convex and 

 broad. Sternum twice as long as broad, or else but very little longer than broad ; 

 furcula ankylosed or not ; only one lateral xiphoid process on each side. 



DESCRIPTION OF THE PLATES. 



(In Plates LV., LVL, LVIL, & LVIIL, the following letters have throughout the 



meanings here given.) 



ac. Preaxial surface of centrum. 



az. Praezygapophysis. 



c, Catapophysis. 



c'. Eidge extending postaxially from catapophysis. 



eg. Groove internal to catapophysial ridge. 



d. Diapophysis. 



/. Foramen in catapophysial ridge. 



g. Groove external to catapophysial ridge. 



h. Surface for head of rib. 



hp. Hyperapophysis. 



Tip'. Small process, preaxial to hyperapophysis. 



hy. Hypapophysis. 



Tiy', Lateral parapophysial ridge. 



t'z. Interzygapophysial ridge. 



m. Metapophysis. 



MS. Neural spine. 



o. Odontoid process. 



of. Foramen for odontoid process. 



p. Parapophysis. 



