— — I 



308 PALEONTOLOGY. 



vary apparatus in Saiirillus. The teeth are implanted accord- 

 ing to the pleurodont type. Supposing the fossil to have come 

 from a mature individual, the size of the animal must have 

 been nearly that of the common European lizard, Lacerta 

 agilis. It was most probably insectivorous. The specific 

 name, " dbtusus" refers to the obtuse termination of the muzzle, 

 as indicated by the form of the fore part of the jaw, and also 

 to the blunt apices of the conical teeth. 



In the slab of Purbeck fresh-water stone containing the 

 portions of upper and lower jaw, with teeth, on which the 

 genus Maccllodon* is founded, were also specimens of small, 

 pitted, dermal scutes, and of a vertebral neural arch, corres- 

 ponding proportionally in size with the teeth. 



One specimen consists of the right superior maxillary 

 bone, containing eight nearly entire teeth, and shewing the 

 places of attachment of thirteen or fourteen such teeth, the 

 mode of attaclrment being by partial anchylosis to the bottom 

 of an alveolar groove and to the side of an outer alveolar wall. 

 Fig. 106, a, shews the dentary element of the lower jaw, con- 

 taining thirteen teeth, and alveolar depressions for twenty ; 

 the bone, which is nine lines long, pre- 

 sents the posterior notch for articula- 

 tion with the angular and surangular 

 elements ; its outer surface is convex, 

 and perforated at its interior half by 

 a linear series of nervo-vascular canals. 

 Fi g- 106. The crown of the teeth is broad, 



Jaw and teeth of MaceUodon, compressed, with sharp subcrenate 



roae;n. (Purbeck beds). . . 



margins at the apical half, curving in 

 most to a low point at the summit. The older teeth have the 

 crown reduced by attrition to the shape of a spade, suggest- 

 ing the name of the genus. The enamel is marked by very 



* Makella, a spade ; odons, a tooth. Quarterly Journal of the Geological 

 Society, No. 40, p. 422. 



