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ANNEXE A LA 



et, notamment, par M. C. W. Andrews, Senior Assistant au British 

 Muséum, qui écrivait tout récemment (1) : 



Fig. 1. — Ophthalmosaurus icenicus, Seeley, 1874. 



Crâne : Face postérieure. — Échelle : | environ. 

 Terrain : Oxfordien (Jurassique supérieur). 

 Localité : Peterborough (Northamptonshire). 

 Ordre : Ichthyosauriens. 

 D'après M. C. W. Andrews (Geological Magazine, 1907, p. 204). 



boc — Basioccipital. 



op. — Opisthotique. 



pt. — Ptérygoïde. 



q. — Quadratum. 



soc. — Susoccipital. 



st. — Columelle (Stapes). 



« The stapes (st.), which, as usual in the group, have lost their audi- 

 tory function, unité fîrmly with the basi-occipital by their expanded 

 inner ends, while their outer extremities fît into pit-like lacets of the 

 quadrates; below they lie in a groove on the upper surface of the 

 pterygoids (pt.), the postero-external wings of which also unité fîrmly 

 with the inner surface of the quadrates. » 



(1) C. W. Andrews. Notes on the Osteology of Ophthalmosaurus icenicus, Seeley, an 

 Ichthyosaurian Reptile from the Oxford Clay of Peterborough. Geological Magazine. 

 Vol. IV. 1907. p. 203. 



