238 
M. Pt.—Meta-pterygoid. f 
m. +. u.—Macula acustica recessus utriculi. 
Ms. Pt.—Meso-pterygoid. 
Ma.—Maxilla. 
mex. V.—R. maxillaris trigemini. 
N.—Cup shaped cavity at each end of centrum containing vestiges of the 
notochord. 
N. A.—Neural arch. 
Ne.—Notochord. 
N. C.—Notochordal canal in centrum placing the notochordal spaces (N.) 
in communication. 
2. Ch. 
ee —Right and left nasal chambers. 
n.ch 
n. olf. ) : 
n. olf eo and left olfactory nerves. 
N. S.—Neural spines, numbered from before backwards. 
N. S.t—Last three neural spines. 
n. sac.1*—The five right and left nasal sacs. 
ee pe | wx splanchnici. 
N. Sp. 
O.C.—Occipital condyle. 
Oc. S.—Occipital spine. 
Od.—Opening of oviduct. 
Od.’—Common oyarial chamber. 
Od.“—Interior of right ovary. 
o. 7.—Branch of the N. oculomotorius to the inferior oblique muscle. 
OE | —Right and left series of olfactory laminz. 
o. lam.’ | 
Op.—Operculum. 
Op. O.—Opisthotic. 
0. pr.—Nervus ophthalmicus profundus (trigemini ?) and ganglion. 
op. 8. vii.—R. opercularis superficialis facialis. 
0. s.—N. patheticus to superior oblique muscle. 
oto.—Saccular otolith. 
out. buc.—R. buccalis externus facialis. 
Pa.—Palatine. 
pal.—R. palatinus facialis. 
p. a. l.—Papilla acustica lagene. 
Pa. P.—Parotic process of pterotic and opisthotic. 
i ee 
