Geological Society of London. 235 



the specimen itself has been referred by Prof. Marsh to the last-named 

 geniis. The genera named were, however, placed in distinct Dinosaurian 

 suborders, and consequently it was evident that the pubic bones by 

 themselves were insufficient for generic determination, whilst the 

 dorsal vertebra of the Wealden fossil had the texture usually found in 

 Dinosauria, and not that peculiar to C'oslurus. The mode of attachment 

 of the ribs was also diiferent. The sacrum of Ccelurus was unknown, 

 but was probably very different from that of Aristosuchus. In the 

 latter the transverse processes or sacral ribs were given off from each 

 individual vertebra, as in certain American forms, and not as in 

 I(/uanodon, HylcBosaurus, Megalosaurus, etc., from the junction between 

 two centra. 



The five sacral vertebrce of the fossil and their apophyses were then 

 separately described in detail, and also an associated fragmentary 

 caudal vertebra ; and the conclusion was expressed i\idit Aridosuchus 

 was a Dinosaur nearly related to certain imperfectly-described American 

 types, such as Allosawus. 



3. "On Patricosaurus merocratus, a Lizard from the Cambridge 

 Greensand, preserved in the VVoodwardian Museum of the University 

 of Cambridge." By Prof. H. G. Seeley, F.R.S., P.G.S. 



No Lacertilian has hitherto been described from the Cambridge 

 Greensand. The only remains of Lizards known to the author as 

 having been derived from that bed consisted of the two bones now 

 described, the proximal end of a femur, and a sacral vertebra with the 

 processes broken away. The former exceeded in size the corresponding 

 bone of the largest living Monitor, and differed from the femora in all 

 recent Lizards in so many respects as to indicate subordinal distinction. 

 The vertebra was not found with the femur, and may have belonged 

 to a different species ; but there being nothing in the characteristics 

 of the two bones inconsistent with their having belonged to one 

 specific type, both were fully described as types of a new genus and 

 species. 



4. "On Seterosuchus valdensis, Seeley, a procoelian Crocodile from 

 the Hastings Sands of Hastings." By Prof. H. G. Seeley, P.R.S., 



r.G.s. 



An ironstone nodule from the Hastings Sands was acquired by the 

 British Museum from Dr. Mantell's collection. The specimen measured 

 10 centimetres by 6, and displayed on its water- worn surface several 

 procoelian vertebrae of a small Crocodilian, together with some other 

 bones, perhaps belonging to a different reptile. These other bones 

 appeared to comprise portions of a skull with peculiarities not hitherto 

 recognized in procoelian Crocodiles, and a pubis and ischium exhibiting 

 distinct Lacertilian characters, and of comparatively very small size, 

 but still situated in proximity to the sacral vertebrae. 



The vertebrae were described in detail in the paper, and referred to 

 a new genus and species. They included one late cervical vei'tebra, 

 eight dorsal, and two which might be considered as sacral. All 

 appeared to be mature, and were more completely ossified than 

 the same bones in living Crocodiles. The body of each centrum was 

 compressed laterally, the neural arch comparatively depressed and 

 thrown out laterally above by the inferior V-shaped approximation 



