424 PROCEEDINGS OF THE GEOLOGICAL, SOCIETY. [JunC 7, 



shells." In it are imbedded some dermal bony scutes, portions of 

 ribs, the neural arch of a vertebra, and parts of the dentary elements 

 of the rami of a lower jaw with teeth — one (fig. 7) containing thir- 

 teen teeth, the other (fig. 8) four teeth ; in both figures the natural 

 size is given in outline. The teeth are anchylosed to an exterior 

 alveolar wall, and have short, broad, subcompressed, rounded, obtuse 

 crowns {b, b). The hinder teeth show a little increase of size, are 

 more obtuse and compressed, and are slightly expanded. Some of 

 the anterior teeth (fig. 7, a) are a little pointed. The enamel is 



Fig. 7. — Pai-t of the left side of Fig. 8. — Part of the lower jaw, 



the lower jaw, with teeth, of with teeth, of the Macello- 



the Macellodus Brodiei, dxjs Brodiei, Owen. (Nat. 



Owen. (Nat. size, and mag- size, and magnified.) 

 nified.) 



a, J. Two of the teeth magnified. b. One of the teeth magnified. 



polished, but is marked by fine longitudinal grooves as it approaches 

 the summit of the crown, hke those in the upper jaw of the Ma- 

 cellodus ; from which character, and from the progressive acquisition 

 of a similar spade-like shape of the crown, as the teeth recede from 

 the apex of the jaw, I conclude that the present is the lower jaw of 

 the same species. The teeth are separated on the average by a space 

 equal to the antero-posterior diameter of the crown ; but some are 

 closer together, others wider apart. The dentary bone (fig. 7) con- 

 taining them exhibits a wide posterior notch for articulation with the 

 angular and surangular elements. The outer surface of the dentary 

 element is smooth and convex. The teeth are much smaller in pro- 

 portion to the jaw than m the Nuthetes, figs. 1 & 2, and evidently 

 belong to a distinct genus of Lizard. 



The dermal scutes are subquadrate, smooth, and slightly concave 

 on the imier surface ; they are impressed with small roimd pits on 

 the outer surface, as in the existing loricated reptiles ; but the teeth 

 in the portions of jaw in the same block are anchylosed to the jaw, 

 not lodged in distinct sockets as in the Crocodilia. In a specimen 

 of two of these scutes in natural juxtaposition, one slightly overlaps 

 the other. The neural arch of the vertebra in the same block ex- 



