lO BAUR. [Vol. VII. 



characters of this family consist in the presence of an inter- 

 clavice and of a median basioccipital canal and the hypobasilar 

 canals. I do not think that this family can be admitted. 



In his first paper on Hainosaurus,^ we find some osteological 

 notes on the Mosasauridae. 



It is shown that the peculiar oval pit on the inside of the 

 quadrate is for the reception of the suprastapedial cartilage, and 

 the name suprastapedial groove is introduced. It is stated that 

 the nasals are co-ossified with the premaxillaries, " comme c'est 

 le cas habituel chez les Mosasauriens." It seems, therefore, 

 that Dollo changed his former view in regard to these elements 

 in Mosasauriis Maxiniiliani. The peculiar arrangement seen in 

 the basioccipital and basisphenoid of Plioplatecarpus and the 

 clavicle of this genus are described. These conditions are 

 more fully discussed and figured in his Notes d' ost^ologie ej-petolo- 

 gique. In a paper, Siir Ic crane dcs Mosasauriens^ the relations 

 of the suprastapedial groove are fully discussed and figured. 

 Figures are also published of parts of the skulls of Mosasaurus 

 and Hainosaurus. In a still later paper three new genera and 

 a new species are shortly characterized and figured, but no new 

 points of importance are brought out.^ 



In a paper just received, the quadrate of Mosasaurus and 

 Plioplatecarpus is described and figured, and some ideas on the 

 phylogeny of the Mosasauridae are expressed. 



Description of the Elements of the Sknll of Platecarpus 

 Coryphcens, Cope. 



Fortunately the skull was fully macerated before it was 

 covered by the matrix. It was possible, therefore, to work 

 out every bone separately and to compare it with the correspond- 

 ing element of the Lacertilia. All the bones are preserved 

 with the exception of the lachrymals and perhaps the ecto- 

 pterygoids.* 



1 Dollo, L., Premiere note sur le Hainosaure, Alosasaurien nouveau de la craie 

 brune phosphatee de Mesvin-Ciply, prh Mons, Bull. Mus. Roy. Hist. Nat. Belg., 

 Vol. IV, 1885, pp. 25-35. 



2 Bull. Scientif. de la France et de la Belgique, Paris, 1888. 



^ Dollo L., Premiere note sur les Mosasauriens de Mesvin, Bull. Soc. Belg. Geol., 

 Vol. Ill, 1889, pp. 271-304, pis. ix, X. 



* The specimen was found by me July II, 1890, and personally exhumed with the 

 greatest care in the course of two weeks. At first nothing but a caudal vertebra was 



