2 BAUR. [Vol. VII. 



Ciivier} 1 808-1 836. 



Cuvier considers the skull of the historical Mosasaurus from 

 Maestricht, which is known to everybody, as intermediate in 

 osteological characters between the monitors and iguanas. 

 The figure published shows both the halves of the lower jaw, 

 the left maxillary complete, the anterior portion of the right 

 maxillary, and both the pterygoids. What is considered by 

 Cuvier as the right pterygoid is really the left one, and vice 

 versa. The four processes of the pterygoid are correctly iden- 

 tified with the corresponding processes seen in this element in 

 Iguana and Monitor. The lower jaw is also compared with 

 that of Monitor, and it is stated that " la composition de cette 

 machoire annonce de plus grands rapports avec le monitor 

 qu'avec aucun autre saurien." Besides these bones others have 

 been worked out afterwards from the matrix of the same piece. 

 A cast which I have seen lately in the Museum at Cambridge, 

 Massachusetts, exhibits a complete quadrate and jugal. 



Goldfuss^ 1834- 



In 1834 Goldfuss gave a very exact description, with splendid 

 figures, of a skull of a Mosasaurus found in the vicinity of Big 

 Bend, on the Upper Missouri, and presented by Maximilian 

 Prince of Wied, then travelling in America, to the Academy 

 of Bonn. This is by far the best account given of the mor- 

 phology of the Mosasauroid skull ; and if this important paper 

 had been studied more carefully by subsequent writers, much 

 confusion could have been spared. 



The skull is in splendid condition. " Es fehlen ihm nur die 

 Schnauzenspitze und die zochbogen (jugal), sowie das Schlae- 

 fenbein (quadratojugale), und der Pauken- (quadratum), und 

 Zitzenknochen (squamosum) der einen Seite." 



The following bones are described : the single premaxillary, 

 which is co-ossified with the single nasals, forming one element ; 

 the maxillaries ; the single frontal, showing traces of original 



1 Cuvier, Baron G., Sur le grand animal fissile des carieres de Mastricht, Paris, 

 Ann. Mus. Hist. Nat., XII, 1808, pp. 145-176, pi., reprinted in different editions of 

 the Ossemens fissiles. 



- Goldfuss, Dr. August, Der Sch'ddelbaudes Mosasaurus, durch Beschreibiing 

 einer neuen Art dieser Gattung erlautert, Aiad. Leon, Vol. XXI, PI. vi-ix. 



