9 
narrower anterior prolongations of the palatines are confluent with the palatal processes 
of the maxillaries (Pl. I. fig. 3, 21), near to which they also develope from their inner 
border a low vertical ridge, The upper surface of each palatal, near its middle part, 
deyelopes the curved outer wall of the posterior nostril, which is convex externally; the 
palatal terminations of these nostrils are longer and narrower, and are divided by the 
compressed elongate vomer (13). 
The nasals, confluent behind with the frontals, prefrontals, and lacrymals, soon divide 
into their premaxillary (ib. fig. 2, 15) and maxillary (15°) branches; the former, at 
first divided by a fissure from the nasal part of the premaxillary (22), coalesce therewith 
anteriorly ; the longer styliform maxillary processes coalesce by their lower end with the 
maxillary. 
The broad part of the palatal plate of the maxillary (ib, fig. 3, 21), whence its palatine, 
malar, nasal, and premaxillary processes diverge, is perforated by the oblique foramen (() 
conveying the lacrymal and superorbital secretions to the angle of the mouth. The pre- 
maxillary processes are divided by the back part of the long prepalatine fissure (7), 
about 2 lines in breadth. The malar process is depressed, about an inch in length, and 
underlaps the fore half of the malar, The nasal process rises to the inner side of, and 
is partly confluent with the maxillary process of the nasal bone; which process 
(ib, fig. 1, 15') is subeylindrical, and extends downward and forward from the interspace 
between the lacrymal bone and the premaxillary part of the nasal, dividing the large 
external nostril ( 15’) from the antorbital ( 21") vacuity. 
The premaxillary chiefly forms the compressed, subarcuate, pointed upper mandible, 
which is grooved on the narrow palatal surface (ib. fig. 3, 22") for an extent of | inch 6 lines 
from the apex, where the prepalatal vacuity commences. The fore end of the groove is 
divided by a short delicate median ridge. The nasal process of the premaxillary (22) 
assumes behind the rostral part of the bone a trihedral shape, gradually becoming flat 
and then concave below; it is grooved above, the groove deepening to a fissure, and 
dividing the back part of the process where it joins the frontal. The nasals (15) are also 
partly divided by linear fissures from this part of the premaxillary, with which they are 
confluent at both ends. 
The pterygoids (fig. 3, 24) are slender, slightly bent, trihedral bones, articulating ante- 
riorly to short pterygoid processes at the inner and back part of the palatines, and pos- 
teriorly with an articular tubercle on the inner side of the base of the inner division of 
the lower articular end of the tympanic (28). The limits of the styliform malar 
(ib, fig. 8, 26) and squamosal (27) are indicated by grooves ; the latter articulates with 
the outstanding lower and outer angle of the tympanic. 
The tympanic articulates by two convex condyles with the mastoid and paroccipital ; 
its body slightly contracts below these, and sends from its fore part a long compressed 
triangular process, with the apex obliquely truncate ; its lower end is much expanded, 
and supports two articular surfaces: the outer one (fig. 3, 28) is oblong and oblique, 
B 

