106 
A Sup:posed Mammalian Tooth. [''j'':^ZXs'!f!^^^^' 
diameters, and exhibits the dentigerous tubules extending from the 
pulp cavity to the enamel, but not entering it ; the tubules anasto- 
mose, and occasionally divide dichotomously ; they are bolder in 
this portion of the tooth than at the apex. 
1 
{ I J!-^ FSG.6 
Fig. 5 c represents a portion of the upper part of the roots of 
the tooth near the point of junction of the two fangs, and is cha- 
racterized by minute pittings, and irregular, broad, but faint 
transverse lines ; it is also magnified 250 diameters. 
Fig. 6d is that portion of the jaw near the point of sym- 
physis, and between the roots of the tooth and the anterior 
extremity of the jaw ; it is a very open structure, not much unlike 
the substance of the oral armature of some of the Ctenodi ; and 
covering the entire surface of the fragment of the jaw there are 
numerous lacunae or radiating bone-cells. Any information which 
will lead to the identification of this apparently unique Coal-measure 
fossil will be esteemed a favour. 
