1897.] FBOM NOBTH ACTSTBALIA, 331 



almost equalling the greatest combined breadth of the nasals. 

 Naso-premaxillary suture not longer than the naso-m axillary 

 suture. Nasal notch rather deep, nasals projecting about 5 mm. 

 beyond their junction wdth the premaxillae. 



Interorhital region very deeply concave in the middle, its edges 

 raised up into high, prominent, sharp-edged ridges, running parallel 

 and not uniting behind. 



Meatus auditorius externus swollen (as in P. peregrinus) ; bullaa 

 not inflated. 



Anterior palatine foramina short, barely extending backwards 

 to the level of p^. 



Posterior palate with two large foramina, extending from the 

 anterior border of m'^ to beyond »i*, and only separated from the 

 border of choanae by a thread-thick bony bridge. 



Teeth. 



Teeth strong. The diastema between i^ and c is 2-3 mm. ; 

 length of molars 1-3 together about 13 mm. 

 The typical dental formula is : — - 



. 1.2.3 1 ■ 2 . .3 1 1.0.3.4 1 ■ 2 ■ 3 . 4 



*• 1 . . *^^ 1 . 2 . U » '^- q] P' 0,0.0.4 5 ™- 1.2.3.4* 



Upper jaw. — Incisors : anterior incisors separated in front ; 

 i^ elongated horizontally, its antero-posterior diameter equalling 

 twice that of i^. 



Distinct diastemata in front of and behind the canine. 



Canine present, small, half the size (or less) of i' ; in one speci- 

 men it is absent on one side. 



Premolars. P^ present or absent, rudimentary, smaller than the 

 canine ; in three of eleven skulls it is absent on one side\ 



P^ absent ; in one of eleven skulls (the largest of all) it is present 

 but perfectly rudimentary, its crown hardly being raised above 

 the gum ^. 



P'^ and p^ always present ; size of p^ about half that of p>*, the 

 latter about two-thirds the size of m^. 



Molars large, typical ; length of molar series reaching 17 mm. 



Loiver jaiv. — Incisors. /^ long, lancet-shaped, broadest in the 

 middle (as in Ps. alhtrtisi) ; upper and lower edge with an angle 

 separating the enamel-covered cutting portion from the root, which 

 is narrower. 



P present or absent, always minute ; in eleven skulls it is 

 present in five, absent in six. I^ always absent. 



Canine absent. 



Premolars. P' absent or present ; in four skulls of eleven it is 

 present, minute ^ 



^ The dental formula in these three specimens is : on one side p. „''",, , , on 



1034 ■'O.O.O.'l 



the other side (typical) "^'q' 



1 2.3.4 



■■^ In this specimen, a male, the formula is on both sides : j). ofoTotl- 



^ Dental formula in these specimens : p. f^o q 4* 



22* 



