120 Transactions. — Zooluyy, 



tooth-like points.* The teeth are mostly broadly conical, 

 especially the maxillary, with their tips truncated or flattened, 

 as if worn ; and all with an apparent longitudinal flaw, or crack, 

 extending down the centre of the tooth. At the same time, it 

 seems to me that the structure of the substance of the teeth, 

 from their semi-pellucid appearance, is different from that of 

 the common bone of the jaws, 



I. Of the Teeth :— 



1. The maxillary, or upper jaws : One contains 16, and one 

 17 teeth, of which the central ones are the largest ; in this 

 respect differing largely from Sphenodon punctatum (Gunther's). 



2. The mandible, dentary, or lower jaws : One contains 16 

 teeth, and a canine one at the anterior end of the jaw, with 

 no space between them ; and one contains 13 teeth with the 

 canine one, and a space between them. These dentary teeth 

 are alternately large and small. 



3. The palatine teeth also vary in number. In the one, there 

 are 8, and in the other 10, teeth, the anterior tooth being 

 the largest. This one agrees with 8. punctatum (Gunther's). 



4. The intermaxillary teeth (if there ever were any) are 

 missing. 



Here, I may observe, that Dr. Giinther says of the teeth 

 of Siohenodon punctatum : — " There are originally about 18 in 

 each maxillary, and 11 in each palatine. However, those of the 

 anterior half of the maxillary appear to be soon ground down 

 to the alveolar edge. . . . The first palatine tooth is much 

 stronger than, and separated by a short interspace from, the 

 succeeding. . . . The alveolar edge of the mandible is 

 polished, bearing about 16 teeth as long as the number is 

 complete ; but (as in the maxillary) the teeth are gradually lost 

 from the front backwards." Dr. Giinther has also given several 

 drawings of the teeth and jaws of Sphenodon punctatum, of 

 both old and young specimens, but none of them agree with 

 these of this specimen. 



II. Of the Dental Bones: — 



1. The upper jaw contains 10 foramina maxima superiora : 

 of these, Dr. Giinther merely says that " they are present as 

 in other lizards." 



2. The lower jaw contains 6 to 7 foramina mentalia: in S. 



*As an apt illustration of this, I may here quote what Dr. Newman 

 incidentally mentions in his paper above referred to : — " Drs. Giinther and 

 Knox disagree in the number of teeth assigned to each maxilla and palate, 

 but this arises from the fact that Dr. Knox considers several of them 

 complex teeth, while Dr. Giinther counts each cone as a distinct tooth. 

 Giinther says there are about eighteen teeth in each maxilla, which Knox 

 counts as six. I counted sixteen in mine, and thirteen on each palate." — 

 (I.e., p. 232.) 



