128 -R- Etheridge: 



cluuiucl are tlie concave surfaces of attachment of seven pleurodont 

 teeth (PI. 8, tig. 2), another with tlie dental tissue remaiiiirtg on it, 

 and the l^ase of a ninth, the tooth fractured transversely, and dis- 

 playing the pulp cavity. At the base of the tooth represented by 

 dental tissue may be seen the foramen leading into the space in 

 which a new successional tooth would be developed. l 



The dental impressions (PL 8, fig. 2) along the alveolar channel 

 average one and three-eighth inches vertically by five-eighths of an 

 inch transversely, but the immediate surface of tooth attachment 

 averages six-eighths by five-eighths. The base of the remaining 

 tooth is longitudinally grooved as in the better of the two figured 

 by Owen as Notiosaurus dentatus,^ indicating the inflected folds of 

 the external cement. 



There are six foramina on the exterior of the dentary of the 

 maxillary artery branches, the second in retiring order double, the 

 sixth and last again double, but the two meati are united whilst 

 still exhibiting evidence of a former separation. This posterior 

 " dumb-l>ell "-shaped foramen enlarges inwards and upwards im- 

 mediately beneath the lachrymal bone (PI. 8, fig. 1). 



In the Water Monitor {Vaiajni,^ ^alvator) these foramina are nine 

 in number. The posterior terminal is simply transversely elongated 

 instead of dumb-bell shaped, and it is the most anterior, instead of 

 the second anterior as in Meficlania, that is double. In the Aus- 

 tralian V . varius, Shaw, there are again nine foramina, all single, 

 and the posterior opening as in V. salvator. 



Jof/osaurus dentatus, from Cuddie Springs, New South Wales, it 

 is true, was established^ by Owen on a mere fragment of the dentary 

 element of a mandibular ramus with portions of two teeth, but the 

 form of these teeth, method of implantation against the alveolar 

 wall, and nature of the cement infoldings are so essentially those 

 of the dentary portion accompanying the Megalania vertebrae, that 

 I have no doubt of their identity. I very much doubt if the tooth 

 figured by Mr. de Vis as yotiosaurus dentatus^ is in any way related 

 to Owen's fossil of the same name. 



The words of Owen, in describing the dentition of the Crocodilian 

 Monitor (V . vrocodilinus) apply so well to the present specimen, that 

 I cannot refrain from quoting them. The teeth " are anchylosed 

 by the whole of their base, and by an oblique surface leading up- 



1 Tims. Tomes' Man. Dental Anatomy, 7th Edit., 1914, p. 310 



2 Owen. Phil. Trans., 175, pt. i., pi. 12, fig. 26. 



3 Owen. Ibid., p. 249. 



4 De Vis. Proc. Ko.v. Soc. Queensland, ii., 1S86, pi. iii., fig. 2. 



