Vol. 63J] SKELETON OE GONIOPHOLIS CBASSID&NS. 55 



border; also that the premaxillae described by Owen l do really 

 belong to Goniopholis erassidens. 



The orbits (PI. II, I) are ovoid. Their posterior borders are 

 high. Laterally they gradually decline on to the lachrymals. 

 Here a deep and wide groove divides them. Prom the bottom 

 of this groove to the summit of the supraorbital rim there is a 

 vertical elevation of 49 millimetres (2 inches). 



Any other than a forward vision was precluded. The type- 

 skull of GoniopJiolis simus is so flattened by pressure, and the 

 boundaries of the orbits so much destroyed, that it is impossible to 

 say how near in this respect they approached to those of the skull 

 under consideration ; and Prof. Dollo does not refer to this in his 

 previously-mentioned description of the Bernissart specimens. 



The supratemporal fossae (PL II, m) are very large, almost 

 twice the size of the orbits. Their inner and posterior margins form 

 curves, while their outer and anterior margins are nearly straight, 

 forming a right angle at their junction. 



The lateral temporal fossae (PI. IY, fig. 1, ct) are large, as is 

 also the tympanic cavity (PI. IY, fig. 2, a). These fossae are 

 divided by a postfrontal and jugal bar. The orbits apparently do 

 not communicate with them. 



The palatines (PI. Ill, a) continue with nearly the same width 

 as when they leave the pterygoids, to half their length. Here they 

 expand, meeting the maxillae 31 mm. from the front extremity of 

 the palatal fossae. Their posterior extremities form only the extreme 

 anterior boundary of the posterior nares, for they immediately 

 connect with, and become exterior to, a process thrown out by the 

 pterygoids. 



The pterygoids (PI. Ill, 6) have their posterior borders much 

 damaged. They appear to widen gently from their median suture, to 

 their contact with the mandibles. Here they have a short expansion, 

 then curve inwards to the palato-pterygoid vacuity. Anteriorly, 

 they throw out a process which forms the lateral borders of the nares, 

 and outwardly a portion of the margins of the palatal fossae. 



The transpalatines (PI. Ill, c) sweep round from the ptery- 

 goids to the maxillae, narrowing the hinder breadth of the palatal 

 vacuities. Their surface on their inner and outer moieties is 

 concave, and convex on the median. 



The posterior nares (PI. Ill, /) are divided by a pterygoid 

 septum, and are twice as long as wide. The palatines border only 

 their extreme anterior point, the pterygoids forming the remainder 

 of their margins. 



The median eustachian canal (PI. Ill, g) is large. It is 

 situated wholly on the pterygoid plane, very near to the posterior 

 nares. 



The palato-pterygoid vacuities (PI. Ill, e) are long and 

 oval, with their posterior end contracted by the inward curve of 

 the transpalatine bone. 



1 ' Monograph of the Fossil Reptilia of the Wealden & Purbeck Formations ' 

 Suppl. viii (Palseont. Soc. 1878) p. 4 & pi. i. 



