METEIOEHYNCHUS LEEDS1. 195 



E. 2042 (Leeds Coll. 17). Imperfect skull and mandible, teeth, imperfect atlas and axis, three 

 other cervicals, and twenty other much crushed vertebrae, numerous fragments of ribs. 



The approximate dimensions (in centimetres) of this specimen are : — 



Skull : length in mid-dorsal line 51-0 



„ to tip of nasals 34*5 



length of nasals 18'5 



distance between nasals and premaxillas 8-0 



least width between orbits 7 - 



distance between outer angles of prefrontals .... 12*0 



Mandible : length of symphysis (approx.) 21 - 



E. 2031 (Leeds Coll. 22). A small imperfect and much-crushed skull. 

 The dimensions (in centimetres) of this specimen are : — 



Length from occipital surface to tip of maxillae . (approx.) 43-0 



„ to tip oE nasals 28 - 2 



,, of nasals 16 - 3 



Distance between nasals and premaxillou 9 - 



Width between outer angles of quadrates 13 - 3 



Least width between orbits 5 - 7 



Width between outer angles of prefrontals 109 



Length of the frontal anterior to temporal fossae 7 - 9 



Metriorhynclms leedsi, n. sp. 



[Plate XL fig. 1 ; text-fig. 73, B.] 



Type Specimen. — An incomplete skull (R. 3540) (PI. XI. fig. 1). 



Only the skull is known in this species, and in both the specimens available the 

 premaxillae are wanting. As in M. Iceve, there is no sculpture on the frontals and 

 prefrontals, which exhibit a slightly roughened fibrous appearance ; but the skull, in 

 proportion to its length, is broader and more heavily built than in M. Iceve. The 

 length of the frontal anterior to the temporal fossae is about equal to the least width 

 between the orbits ; in M. Iceve it is much greater. The form of the frontals will be 

 best understood from the figures (PL XL fig. 1 ; text-fig. 73, B) ; the prefrontals take 

 a greater share in the formation of the upper border of the orbit than in M. Iceve, 

 and their orbital edge bears a series of small irregular notches. The nasals are 

 separated from the premaxilla; by a space rather greater than half their own length. 



This species is distinguished from all the others, not only by the smoothness 

 of the skuil-bones, but also by the great number of the teeth. Of these, there are 

 about 3G in each maxilla, the alveoli being separated from one another only by 

 thin walls. 



2c2 



