682 PROF. OWEN ON THE RANK AND AFFINITIES IN 



36. On the Bank and Affinities in the Reptilian Class of the 

 Mosasatjrid^:, Gervais. By Prof. Owen, C.B., F.B.S., F.G.S., 

 &c. (Bead June 6, 1877.) 



§ 1. Introduction. — The fortunate acquisition by the British 

 Museum of the " Van-Breda Collection," which includes the best 

 specimens that have been found since the times of Camper and 

 Cuvier of the large saurian and chelonian fossils from Maestricht — 

 the Mosasaurian fossils brought to Europe from America by Prince 

 Maximilian of Neu-Wied, and by Prof. H. Bogers, of Pennsyl- 

 vania — supplemented by the richer collections of similar fossils 

 from the western Cretaceous beds of the United States, due to the 

 important and praiseworthy labours of Professors Leidy, Marsh, 

 and Cope, — have accumulated a mass of materials by the study of 

 which the rank and affinities in the Beptilian class of Mosa- 

 saurus and its near allies can, as I believe, be definitely determined. 



When Cuvier * initiated the present inquiry his subjects had been 

 referred to the Cetacea by Camper f, and to the Grocodilia by 

 Faujas X '■> and Cuvier's comparisons, leading to the conclusions as to 

 the closer affinities of the fossils to the Lacertilia, are preceded by 

 the classical ' Osteologie des Lezards,' from which he derives most 

 of his illustrations of the genus which Conybeare had called Mosa- 

 saurus. 



To the Ophidian order Cuvier makes but one reference, which is 

 decisive as between Serpents and Lizards § ; and he seems to have 

 felt as little called upon to discuss the osteology and dentition of 

 Fishes for a refutation of an early reference of parts of the Mosa^ 

 saurus to that class. 



The question, however, of the relations of Mosasaurians to Ophi- 

 dians has of late grown to dimensions which command more de- 

 tailed comparisons from the palaeontologist who may be moved to 

 discuss it. 



In the ' Proceedings of the Boston Society of Natural History ' 

 for 1869 (p. 250), Prof. Cope determined the Mosasauroid character 

 of certain Cretaceous fossils ; he deduced from them the number of 

 the cervical vertebrae, the structure of the posterior regions of the 

 cranium, of the lower jaw, scapular arch and fore limb, and dia- 



* Eecherches sur les Ossemens Fossiles, 4to, 1824, tome v. 2de partie, 

 p. 310. 



t ' Philosophical Transactions,' 1786. 



t Histoire Naturelle de la Montagne de Saint Pierre, p. 40. 



§ Professor Cope meets the argument by denying the homology on which 

 Cuvier founded it. Cope's " palatine bones," are, he affirms, " the pterygoids of 

 Cuvier. The true pterygoids are rather short compressed bones, which are 

 united by suture to the borders of a concavity of the palatine. They are tooth- 

 less, and have no sutural connexion with the ossa quadrata." — Beport of the 

 United- States Geological Survey of the Territories, vol. ii. ' The Vertebrata of 

 the Cretaceous Formations of the West,' 4to, 1875, p. 118. 



