382 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 



M. Pt. — Meta-pterygoid. 



m. r. u. — Macula acustica recessus utriculi. 



Ms. Pt. — Meso-pterygoid. 



Mx. — Maxilla. 



mx. v. — R. maxillaris trigemini. 



N. — Cup shaped cavity at each end of centrum containing vestiges of the 

 notochord. 



N. A. — Neural arch. 



Nc. — Notochord. 



N. C. — Notochordal canal in centrum placing the notochordal spaces (N.) 

 in communication. 



' [ — Right and left nasal chambers. 

 n.ch. 1 I 



,' I — Right and left olfactory nerves. 

 n. oip j 



N. S. — Neural spines, numbered from before backwards. 



N. S.f — Last three neural spines. 



n. sac. 1 - 5 — The five right and left nasal sacs. 



,, [ — NN. splanchnici. 



n. sp. J 



O.C. — Occipital condyle. 



Oe. S. — Occipital spine. 



Od. — Opening of oviduct. 



Od/ — Common ovarial chamber. 



Od." — Interior of right ovary. 



o. i. — Branch of the N. oculomotorius to the inferior oblique muscle. 



- — Right and left series of olfactory laminae. 

 o. lam.' j 



Op. — Operculum. 



Op. O. — Opisthotic. 



0# p r , — Nervus ophthalmicus profundus (trigemini ?) and ganglion. 



op. s. vii. — R. opercularis superficialis facialis. 



0# s . — ]Sf. patheticus to superior oblique muscle. 



oto. — Saccular otolith. 



out. hue. — R. buccalis externus facialis. 



Pa.— Palatine. 



pal. — R. palatinus facialis. 



p. a. I. — Papilla acustica lagense. 



p a , p. — Parotic process of pterotic and opisthotic. 



