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A Secondary Reptile from Madagascar. 195 
contained in the portion attached to the limestone; the left has 16 
alveoli; therefore calculating 4 for each preemaxilla we may roughly 
assume that the total number of teeth for this animal was from 116 
to 120. 
The alveolar cavities are large, round, of a slightly varying 
diameter, and separated by wide and excavated interspaces which 
produce rather bold marginal serrations; the palatal surface lies 
just below the alveoli. 
The premaxille are swollen and truncated, but so mutilated in 
front that only the first and second alveoli are traceable on each 
side; the suture follows a rectangular course on the palatal surface, 
then passes closely by the first maxillary alveolus to continue its 
direction over the upper surface, where it makes a deep posterior 
descent and terminates in an acute angle. 
At the transverse fracture of the rostrum the narial passage is_ 
observed to be cordiform in shape, with the apex pointing upwards; 
the obliquely set condition of the teeth can be also seen here. 
The Mandible is long and narrow with a depressed dentary plateau, 
basal surface slightly convex and with vertical sides; it measures 
62 centimetres in length, has a maximum thickness of 3 cent., and 
the posterior ends of the splenials are 13 cent. apart. The man- 
dibular rostrum is widest at the 23rd alveolus where it measures 
6 cent., gradually decreasing to half that width at the 6th and 7th 
alveoli. The dentaries dilate at the 3rd and 4th alveoli, afterwards 
tapering off to the part containing the two anterior sockets; a some- 
what deep groove at the anterior end forms their dividing line. 
The symphysis is elongate and narrow, its anterior point being 
distant 50 cent. from the front. The splenial bones are crushed in 
their central parts, but well defined anteriorly and posteriorly. 
Their divergent ends are embedded in the matrix. 
The left dentary shows 26 alveoli, a few of the posterior ones 
being displaced and seen in the matrix; the alveoli similarly 
arranged as in the cranial rostrum, except the 3rd and 4th, which 
are contiguous and occupy the elevated and expanded region of the 
dentaries. The basal portion of the 8rd left dentary tooth is 
exposed on the under surface of the mandible and exhibits one of 
its lateral carinzs, which is smooth and not serrated. 
The nutrient foramina are fairly distinguishable along the alveolar 
borders of both rostra. 
CrantaAL REMAINS IN MATRIX. 
These consist of the occipital region, considerably damaged in 
parts, having a central vertical depth of 10-5 cent., and a maximum 
width of about 24 cent. 
The upper occipital is concave and quadrilateral, with obtuse 
angles possessing a similar depth and width of 38-7 cent. The 
foramen magnum is transversely elliptical, having a diameter of 
4 by 1-4 cent.; the occipital condyle is large, with an imperfect and 
broken surface. To the right of the foramen is a distinct perforation, 
