442 ON THE SKELETAL ANATOMY OF THE MESOSUCHIA. [NoT. 20, 



34. Marsh, O. C— Principal char. Amer. Dinos. Part vi. Am. 



J. Sc. vol. xxvi., Aug. 1883, pp. 82-83. 

 3.0. DoLLO, L. — Cinquieme note. Bull. Mus. Eoy. Hist. Nat. 



Belg. t. iii., 1884, pp. 129-13.5. 



36. Hoffmann. — Reptilien. Bronn's Klassen. 



37. Seeley, H. G. — On the Bone in Crocodilia which is commonly 

 regarded as the Os Pubis. Proc. R. Soc. vol. xliii. no. 261, 

 p. 23.5, Dec. 1887. 



38. Owen, R. — Brit. Foss. Rept. 



39. Seeley, H. G. — Loc. cit. p. 



40. Quenstedt. — Sonst und Jetzt. 18.56. 



41. Fraus. — Paleonfogr, Bd. xxv. oder iii. Folge Bd. 1. Lief. 4, 



1878. 



42. Ztttel. — Ramph. Germ. Paleontogr. Bd. xxix. iii. F. v. 

 Taf. xii. fig. 2. 



43. Baur, Dr.^G. Amer. Nat., 1887. 



44. Koken. — Die Kept. d. N. Deutsch. Kreidcr. Z. d. deutsch. 

 geol. Gessell., 1883. 



45. D' Alton and Burmeister. — Foss. Gav. v. Boll. 



Since writing the above, my attention was lately most kindly 

 called to some remains of Geosaurus in tbe Nat. Hist. Mus., Crom- 

 well Road, by Mr. Lydekker, who at ihe same time pointed out to 

 me such close structural correspondences between these and certain 

 Metriorhynchiau remains from the Oxford Clay, collected by 

 Mr. Leeds, identical with those here described, as are suggestive of 

 a very near affinity between these Saurians. 



Oct. 27, 1888. 



EXPLANATION OF THE PLATES. 



Plate XVI II. 



Metriorki/ntkus. 

 Fig. 1. Side view of synostosed atlas and epistropheus (axis), d', diapo- 

 physis of axis; d, diapopbysis of atlas. 



2. Anterior view of a cervical vertebra. d, diapopbysis ; p, parapo- 



pbysis; ^Jir^, prezyapopbysis ; ^:iS-,. postzygapopbysis. 



3. Anterior view of trunk vertebra. 



4. Posterior view of second sacral vertebrse. 



5. Caudal vertebra. 



Sfeneosmcrus. 



6. Side view of epistropheus. 



Plate XIX. 

 Mctriorhynchis. 

 Fig. 1. Ilium ; left, outer view, pa, preacetabular process ; a.i, anterior 

 ischiatic process ; p.i, posterior iscbiatic process ; s, s, sacral impres- 

 sions ; u, upper border ; a, acetabular bollow. 

 2. Inner view of same bone. 



Sieneosawrus. 

 ' 3. Hium ; left, outer view. Lettering as in figs. 1 and 2. 

 ■ 4. Inner view of same bone. 



5. Isohimn. a, anterior border; m, mesial sympbysial border. 

 (3. Os pubis. 



