MR. TOMES ON THE STRUCTURE OF 
56/l 
PLATE XLV. 
Fig. 35. A longitudinal section of the upper incisor of the Porcupine {Hystrix cristata), 
in which is shown, D, the terminal portion of the dentine with its obliquely 
placed elongated cells, and E, the enamel with its confluent layers of ob- 
liquely placed fibres and the parallel fibres of the outer portion of the tissue. 
120 linear. 
Fig. 36. A transverse section from the same tooth, showing, D, the dentine, and E, the 
enamel fibres pursuing a serpentine course in the lamelliform part of the 
tissue, and a straight parallel course in the external division of the tissue. 
120 linear. 
Fig. 37 . An oblique longitudinal section from a lower incisor of the Spotted Cavy 
{Ccelogenys Paco), showing, D, the dentine with its peripheral layer of cells, 
and E, the enamel with the confluent layers, and with the fibres of alternate 
ones divided more or less transversely. 
Fig. 38. An oblique transverse section from the same tooth, showing, D, the dentine, 
and E, the enamel with the fibres in their waved course in the lamelliform 
portion, and parallel course in the outer portion of the tissue. 
Fig. 39. An oblique transverse section from a lower incisor of Capromys Fournieri, 
showing, D, the dentine, andE, the enamel, which in this figure is rather a 
diagram illustrating the arrangement of the enamel fibres, than a faithful 
delineation of the appearance presented in the section. 
Fig. 40. A longitudinal section from the same tooth, showing, D, the dentine, and E, 
the enamel, with its confluent laminae and the oblique constituent fibres. 
Fig. 41. An oblique transverse section from the same tooth, showing at E the ap- 
pearance assumed by the enamel laminae near the sides of the tooth when 
the fibres are exposed in their length in the middle part of the section. 
PLATE XLVL 
Fig. 42. An oblique transverse section from the upper incisor of Hahrocoma Bennettii, 
showing, D, the dentine, and E, the enamel, with the direction of the enamel 
fibres. 
Fig. 43. A longitudinal section from the upper incisor of Hahrocoma Bemiettii, 
showing, D, the dentine, and E, the enamel with its confluent laminae. 150 
linear. 
Fig. 44. Plate XLV. A longitudinal section from a lower incisor of the Guinea Pig 
{Cavia Aperea), showing, D, the peripheral portion of the dentine with its 
terminal layer of oblique elongated cells, and E, the enamel and its confluent 
laminae. 200 linear. 
