Fig. 79. Transverse section through an intervertebral region of the same larva as fig. 78.
Fig. 80. Side view of two trunk vertebræ of an adult Lepidosteus.
Fig. 81. Front view of a trunk vertebra of adult.
In figures 80 and 81 the red does not represent bone as in the other figures, but simply the ligamentum longitudinale superius.
EXPLANATION OF [PLATES 43]-45. (XXIV. p. 854.)
N. B. The series of sections are in all cases numbered from before backwards.
List of Reference Letters.
a.p. Area pellucida. ep. Epiblast. ch. Notochord. gr. Germinal wall. hy. Hypoblast. m. Mesoblast. o.p. Area opaca. pr.g. Primitive groove. pvs. Primitive streak. yk. Yolk of germinal wall.