\ ” 
* 
206 ON A DENTAL PECULIARITY OF THE LEPIDOSTEIDS. | 
run parallel with the long axis of the jaw and with each other. 
The internal row of teeth are large ee a speaking) i 
placed at distinct intervals . rot ute 
row is formed of a great nu of v very minute teeth (in stab 
ies they aré almost invite to the naked eye), yet 
smooth and istedine on its wxteiviiel surface. On ing a 
vertical section of one of these teeth, the povtiaty "ae the 
arrangement of the enamel is wr eiae more perfoet ly. The tooth 
on this is fitted the “cap” ganoine as fish 
enamel is usually termed, which is also acutely p d ip 
of ganoine, therefore, appears like V closely adjust 
o the aciculated apex of the pon The structure of t Z 
and T Sens give it in extenso. “The enamel or ganoine > tip. is 
composed of aclear, perfectly transparent homogeneous tissue, in 
which ramify numerous tu a “5 which are continuations of the 
tubules that have arisen from ulp cavity and pursued bal 
course through the dentine oun ietberehi between that ‘k 
d the tip. The course of the tubules when they have enter 
d b 
an 
the enamel tip tei le t 
tooth, those in the centre being quite parallel. As the ak 
ah 
ai 
ultimately disappear, very few of them-reaching the periphery 
Ste ; they do not, cpa or ger im a boundary a 
y do in the dentine. "Here again, I do not doubt that the 
tubules do reach the external ceiane but it is or eT to 
trace them on account _ thei ir imixiutericon dn dnd the clearness of 
ee tne? in which they ramify. aa tubules ri are visible 
red stri skin so by the dark carbonaceous matte 
peas: in their interior contrasting with the clear tissue in 
which they are imbedded. In LXVI1 the minute strue- 
ture of the hi is well portrayed ; its form, however, has on 
somewhat des troyed in making the section, the extreme Hp 
ving been rubbed away ; it should bes acutely pointed. I hav 
aided et ee to show the extent to which the enamel 
