LIASSIC FORMATIONS. 



dislocated that side of the upper jaw ; the hind part of this ramus is ol)H(|uely depressed, 

 so as to expose the inner surface (32). 



Tlie anterior entire or undivided part of the i)remaxillary {22) is about 2 inches in length, 

 and \ \ inch in vertical height at its back part: it contains four pairs of teeth, which are 

 the largest and longest of the series. The foremost tooth (1) is terminal, with a crown 

 5 lines in length, rather over 1 line in breadth (fore-and-aft) at its base ; it 'is subcompressed, 

 subrecurved, and sharp-pointed. An interval of 4 lines divides it from the second tooth 

 (2), with a crown 5i lines long. After an interval of 7 lines projects the crown (3) of 

 the third tooth, 7 lines in length and 2 lines in basal breadth, sharp-pointed like the first, 

 but less bent. The socket and base (?) of the fourth tooth appear at an interval of 

 lines, and below is the entire and displaced honiotypal tooth (4') of the left side, showing 

 the cavity on the inner side of its root which would have received the successional laniary. 

 This tooth measures 1 inch 2 lines in total length, of which the exposed enamelled crown 

 forms two-thirds. In advance of the foremost tooth (1) is seen part of its homotype (!') of 

 the left side, also displaced from the socket, and showing the depression and vacuity on 

 the inside of the base, in relation to the succeeding tooth. Beyond the fourth alveolus 

 the maxillary (21) aj)pears, underlapping the part of the preniaxillary (22") which defines the 

 lower and anterior part of the narial vacuity : the maxillary is continued straight backward, 

 with feeble indications of two crushed alveoli (5, e) for 1 inch 9 lines, when the seventh 

 laniary (7) projects almost straight downward: the crown of this tooth is 5 lines long; the 

 root, covered with rougher cement, slightly contracts to its implanted end, which has 

 slipped a short way out of its socket. An interval of 4 lines divides this from the next 

 laniary (s), which shows a crown of but 3 lines in length ; this projects opposite the fore 

 part of the lateral post-narial branch (21'^) of the maxillary. The base of the left 

 homotypal tooth (8') projects from the same part of the dislocated left alveolar branch of the 

 maxillary ; and above this, on the inner side of that bone, is exposed the coronal germ of 

 a successor. In the right maxillary two other straight laniaries (9, 10) of rather decreasing 

 length, project with similar or rather lessening intervals : then follows, after an interval of 

 3 hnes, a pointed compressed crown 1^ line in length (11) ; and, at shorter intervals, 

 two smaller pointed compressed teeth (12 and 13). 



These thirteen cuspidate teeth of the upper jaw are included in an extent of the 

 alveolar border measuring 5 inches 2 lines. That border is continued backward, straight 

 and edentulous, for 9 lines beyond the last tooth, when it is crossed by the large and long 

 first phalanx (/r 1) of the wing-finger. This edentulous part of the maxillary forms the 

 lower straight border or base of the large triangular antorbital vacuity (a), at the back 

 part of which it is overlapped by the fore part of the slender malar (2G). Above this 

 vacuity are parts of the nasal (15) and prefrontal (11), both somewhat displaced in this 

 crushed part of the skull. The arched part of the frontal forming the upper part of the 

 rim of the orbit (o) is recognisable at (11) PI. XVII. Above its hind part are indications of 

 the post-frontal (12) and mastoid (s), with the process of the latter descending external to 



