L'ORIGINE 



DES 



MOSASAURIENSW 



PAR 



Louis DOLLO 



Conservateur au Musée royal d'Histoire naturelle, i\ Bruxelles. 



1. Introduction. — 4. Dans un article assez récent (2), 

 M. S. W. Williston, professeur à l'Université de Chicago, écrit les 

 lignes suivantes : 



« [n 1892 Kramberger-Gorjanovic described from the Lower Creta- 

 ceous (probably Gault) of the island Lésina, near the Dalmatian shores 

 of the Adriatic, the remains of a remarkable lizard, which he called 

 Aigialosaurus. While his figures have recently been shown to be 

 incorrect in some détails, and while some of his minor interprétations 

 were manifestly wrong, he correctly assigned to his new genus and its 

 allies an intermediate position between the true Varanidae and the 

 Mosasauridae, suggesting that they had descended from the Varanidae 

 and were ancestral to the Mosasauria, while from them have been 

 derived the Dolichosaurs as a side branch. 



» His conclusions regarding the relationships of the Mosasauria are 

 the more creditable from the fact that the only information available 

 to him at that time concerning ihem was incomplète, and in part 

 erroneous. Nevertheless, so apparent were they that both Boulenger 

 and Dollo accepted them, recognizing in Aigialosaurus an ancestral 

 type. )> 



2. Sans vouloir méconnaître nullement le service éminent rendu, à' 

 la Paléontologie, par M. G. Gorjanovic-Kramberger, professeur à 

 l'Université d'Agram, en publiant sa description à' Aigialosaurus, — 



(1) Mémoire présenté à la séance du 18 octobre 1904. 



(2) S. W. Williston. The Relationships and Habits of the Mosasaurs. Journal of 

 Geology. 1904. Vol. XII. p. 45. 



