360 Messrs. Hancock & Attliey on Reptile- and Fish-Remains 



row is complete, these large teeth being frequently broken off. 

 Nevertheless in several of our specimens they can be observed 

 arranged at pretty regular intervals, evincing that the series, 

 as far as it extends, is complete. In one mandible, in which 

 the row is nearly entire, there are eighteen or nineteen teeth ; 

 and in the mandible of another species fourteen or fifteen can 

 be counted. The teeth in the maxillae appear to be equally 

 numerous. 



The teeth themselves (PI. XVI. figs. 1 & 2) are, as we have 

 already said, sharp-pointed and conical ; they are a little re- 

 curved, the bend being usually greatest a short way above the 

 base. Fine large specimens are upwards of one-eighth of an 

 inch long ; but they are generally much less ; they vary con- 

 siderably in this respect in the different species. They are 

 most frequently wide at the base, and contract rather sud- 

 denly immediately above ; thence the attenuation is very 

 gradual, until within a short distance of the apex, a little be- 

 low which the crown is slightly swelled ; from this point the 

 sides of the tip incline more rapidly towards each other, and 

 unite to form an extremely sharp apex. In some species the 

 apex is much produced and attenuated, in others it is com- 

 paratively short ; but in all it is characterized by its sharp- 

 ness. The sharp-pointed tip or apex is formed of a thick cap 

 of enamel, and is usually quite smooth and highly polished. 

 Below the cap, in all the species examined, the crown has a 

 subdued lustre, and is fretted in a very beautiful manner with 

 numerous minute, short, close-set, longitudinal depressions, 

 which, being arranged lengthwise, have occasionally a lateral 

 inclination : hence the peculiar fretted appearance of the sur- 

 face. 



On making a longitudinal section (PI. XVI. fig. 2), the pulp- 

 cavity is seen to conform to the shape of the crown ; the 

 cavity is wide below and narrow above, tapering gradually 

 towards the apex, and terminating just within the extremity 

 of the dentine. The tip of enamel fits on to the top of the 

 dentine like a ferrule, and is in the form of an inverted V, 

 with the angle filled up for some distance, and the stout limbs 

 tm-ned out a little below and mortised, as it were, into the 

 dentine. The enamel-cap varies a little in form in the different 

 species; but it varies still more in accordance with the plane 

 of the section. When the section is made directly through the 

 centre, the solid apical portion of the enamel is seen to be 

 much produced, and very sharp. By making the section a 

 little eccentric, the solid tip is reduced in length and sharp- 

 ness ; and by carrying the process a little further, the enamel- 

 cap becomes a mere thin covering, like a transverse section of 



