ON TWO SKULLS FROM THE WEALDEN AND PURBECK FORMATIONS. 377 



21. Note on two Skulls from #i6 Wealden and Purbeck Formations 

 indicating a neiv Subgroup of Crocodilia. By J. W. Hulke, 

 Esq., F.R.S., F.G.S. (Read February 6, 1878.) 



[Plate XV.] 



An examination of the crocodilian skull exhibited last session by 

 Mr. Willett, and of an undescribed skull in the British Museum, 

 No. 41,098*, has brought to light a peculiarity in the posterior nares 

 which, so far as I am aware, had been previously recognized only in 

 the small crocodilian skull from Brook, Isle of Wight, in the Jermyn 

 Street Museum, described by Prof. Huxley in a paper communi- 

 cated to this Society on 28th April, 1 875, and figured in the Quart. 

 Journ. Geol. Soc. vol. xxxi. pi. xix. fig. 3. 



This, and the great probability of the correctness of Mr. Willett's 

 reference of his acquisition to Goniopholis crassidens, the skull of 

 which was before quite unknown, have seemed to me to invest these 

 skulls with sufficient interest to warrant me in offering a short 

 account of them to the Fellows. 



I. Mr. Willetfs Crocodilian SJcull (Goniopholis crassidens, Owen ?). 

 (PL XY. figs. 1 & 2.) 



Viewed from above, the outline of this skull has the form of a 

 slender isosceles triangle, the base of which, taken between the 

 extreme outer posterior angles of the quadrate bones, measures 

 about 13 inches, and the nearly straight sides from the same points 

 to the premaxillary suture 25 inches. The uniform convergence of 

 the sides is broken by a slight inbend in front of the orbits, by a small 

 outbend at the 6th, 7th, and 8th maxillary teeth, reckoned from 

 before backwards, and by the abrupt expansion of the prsemaxillse 

 occasioning a deep lateral notch at their union with the maxillae. 



The upper surface of the skull, behind the orbits, has a nearly 

 oblong figure ; its posterior border measures 8 inches, the anterior 

 border 7| inches, and the lateral borders 5 inches. The temporal 

 openings, of a roughly quadrilateral form, are very large; their 

 antero-posterior diameter is 2| inches, and their transverse mea- 

 surement 2\ inches. The intertemporal part of the parietal bone 

 and the postfrontal squamosal bars are very narrow. 



Between the orbital openings the upper surface of the skull is 

 transversely concave and almost plane sagittally. These openings 

 look upwards and outwards. Their upper border is very prominent, 

 and it has, filling a deep angular notch, wedged in between the post- 

 frontal and prefrontal bone a distinct supraorbital ossification me- 

 sially marked off from the neighbouring bone by a sutural groove 

 distinctly apparent on the upper and also on the under surface of 



* This appears to be the specimen figured by Prof. Owen as Goniopholis simus 

 in the volume of the Palseontographical Society's Memoirs issued since the 

 present paper was written and sent in to the Geological Society. 

 Q. J. G. S. No, 134. 2 c 



