74 Messrs. Hancock & Attliey on a portion oj 



surface is exposed to view, and is concave longitudinallv, the 

 outer surface being a little convex, as is evident in the trans- 

 verse section of the specimen in front. The bone, which is in 

 a very perfect state of preservation, is composed of two paral- 

 lel layers — an inner, the splenial plate (c), and an outer, the 

 dentary piece {d) — and is stout, particularly at the alveolar bor- 

 der, where it is an inch thick ; thence it becomes gradually 

 thinner to the longitudinal middle line ; here it is scarcely 

 more than ^ of an inch thick, and so continues to the inferior 

 margin. 



The upper surface of the alveolar border is slightly chan- 

 nelled, and is almost straight ; but within 3^ inches of the 

 posterior extremity it is bent a little downwards (e), and then, 

 rising up considerably above the level of the border, is con- 

 tinued backwards in a straight line (f) to the posterior extre- 

 mity ; this straight part is 1| inch long, and is bevelled off to 

 a sharp edge. In front of the elevation the alveolar border 

 haa>been torn, apparently by pressure, from the inner layer of 

 bone, which at this part is pushed a little downwards. 



The teeth are well preserved ; in all there have been twelve, 

 nine of which are almost perfect, and, with the exception of 

 the three posterior ones, are all of the same size. They are 

 nearly an inch long, and at the base are upwards of a quarter 

 of an inch wide ; they taper gradually to the apex, which is a 

 little compressed in the direction of the long axis of the jaw, 

 and in the same plane has the sides slightly carinated, and is 

 also rather suddenly bent inwards and backwards ; but the 

 recurving is probably, in part at least, owing to pressure. 

 The crown is not perfectly cylindrical or, rather, conical ; it is 

 a little flattened at the sides, and is therefore in cross section 

 somewhat angulated ; and at the base it is wider in the trans- 

 verse than in the longitudinal direction of the jaw. The 

 whole surface is covered with brilliant enamel, and is longi- 

 tudinally grooved to within less than a third of the apex. 

 The grooves are fine, rather distant, and the spaces between 

 them are flattened, so that there is a tendency to a ridged 

 appearance. 



The teeth are clustered, and in this respect agree with those 

 of the maxillae. In the clusters the bases are in contact ; and 

 short spaces divide the clusters. The first tooth (g) is split 

 longitudinally by the anterior fracture of the specimen, and 

 very little of it remains : only a small piece of the base is per- 

 ceptible ; but a partial impression of the crown shoAvs that it 

 was as large as the others. The base of the second tooth is 

 not far from that of the first, and is the first perfect one of the 

 series. The third tooth has been removed for structural exami- 



