FEB 13 1695 



Kansas University Ouarterly, 



Vol. III. JANUARY, 1S95. No. 3. 



New or Little Known Extinct Vertebrates. 



BY S. \V. WILLISTON. 



(With Plates XIV to XIX ) 



Fifty-two years ago, Dr. Augustus Gokifuss presented to the 

 Geologische Section der Naturforscher-versanimlung zu Mainz tlie 

 description of certain remains of a JNIosasaur discovered some time 

 previously by Major O'Fallen in the vicinity of Big Bend of the 

 upper Missouri river and secured by Prince Maximilian of 'Wied, by 

 whom they were presented to the museum at Bonn. His paper was 

 published two or three years later in the Acta Acad. Caes. Leop. 

 Carol. Nat. Cur., vol. .xxi, with four excellent plates. As Baur 

 has said, had later authorities studied this paper more attentively 

 they would not have claimed as new a number of discoveries 

 made and published long before, among which may be mentioned the 

 position of the quadrate bone, the presence of the quadrato-parietal 

 and malar arches, and the sclerotic ])lates. 



In 1882, DoUo established on this species a new genus, basing it 

 upon the supposed union of the pterygoids in the median line. This 

 character was suspectetl to be a deformity by Cope, and has recently 

 been so established by Merriam.* The other distinctive characters 

 which Dollo gave are unimportant. They are as follows: "Crane 

 comprime de haut en bas. Borde dentaire du pterygoide droit et 

 portant dix dents. Premaxillaire impair avec face superieure 

 aplatie." For Mosasaurus: "Crane plutot comprime lateralement. 

 Borde dentaire du pterygoide recourbe et portant huit dents. 

 Premaxillaire impair avec face superieure en carene."t 



Of these characters, the first does not exist — the pterygoids are 

 not united in the middle line nor are even contiguous. There is 

 no more depression of the skull than occurs in other forms of the 

 order. The specimen described and figured in the present paper, 



*Iii lit. Dr. Merriam has Icinlly communieatel a number of other interestiug facts 

 concerning this specimen, which. with his permission, will be published in a future paper. 

 tBiill. du Mus. Royal d Hist. Nat Bel^- i. P, ', 188--'. 



(165) KAN. UNIV. l^UAH., VOL. Ill, NO. 3, J.*N.. 1895. 



