Mr. T. Atthey on Anthraco.saurus llu.s.sulli. 153 



both sides, determinable. That portion of the surface of the 

 vomer and pterygoid bones which has been preserved is 

 covered all over with small, pointed, and closely set tubercles, 

 while, on the other hand, the ))alate-bone3 are deeply pitted. 



The p^eneral surface of the palate has been disrupted along 

 the median line by the pressure to which the skull has been 

 subjected, thus leaving exposed the greater part of the sphenoid 

 and presphenoid bones, the fissure extending fonvards from the 

 junction of the sphenoid with the presphenoid to a point a little 

 in advance of the position of the palatal tusks. 



The palatine foramen found in Arcfief/osanrus, Tremato- 

 saurus, Mastotlonsatinuij &e. is altogether wanting in Anthra- 

 cosaurus and also in Loxomma. 



The premajciUarics are strong and the bone of the left side 

 is well preserved, showing three teeth, all broken off at their 

 apices. The tooth (or, rather, what remains of it) that is next 

 to the symphysis and the third from it are each -,^ inch long ; 

 the second is ^ inch ; they are equidistant from each other. 

 The right })remaxillary teeth are hidden by the posterior part 

 of the right mandible lying over them. The teeth, when 

 entire, could not have measured more than — inch in length. 



In another pra3maxilla in my possession, a little smaller than 

 the above, there are five teeth closely set together. The first 

 three are | an inch in lengtli ; the two external or posterior are 

 much less. 



The premaxillaries are sutured behind transversely to the 

 vomers. They are said by Prof. Huxley " to send back from 

 their opposed ends two processes which run upwards and back- 

 wards in the middle line (in the manner common in Amphibia) 

 towards the junction of the vomers." These processes do not 

 exist in the above specimen. 



The vomers bear no teeth ; their surfaces, when well pre- 

 served, are seen to be covered all over by small pointed 

 tubercles. They are normally united by suture on the median 

 line ; but in Plate IX. they are represented as having 

 been forced asunder by the crushing of the skull. They 

 articulate by suture, in front, with the premaxillaries, and 

 externally with the palate-bones. Near the base of the 

 great palatine tusk they form the inner arched sides of the 

 nasal channels. Internal to the tusks the vomers are very 

 narrow, but further ])ack expand a good deal outwards, being 

 all along joined to the inner edges of the palate-bones. They 

 are united behind, next the median line, with the pterygoids. 



The nasal channels are directed from the external orifices 

 inwards and backwards towards the median line ; for 2 inches 

 of their course they arc well defined, and measure ^ inch in 



