Stroud, Mavivialian Carbclhnn. 



103 



eptl. — epitela. 



yff.— flocculus. 



Jlc. s. — floccular sulcus. 



/rcl, s. — furcal sulcus. 



g'm. — gemina. 



ist/t. — islhmus. 



kl. — kilos. 



/. ct. — central lobe. 



Ing. — lingula. 



/. £/-(5(j'.— lateral U-like bend. 



mediflc, — medi flocculus. 



mesen. — mesencephal. 



meten. — metencephal. 



mscl. — mesocoele. 



nitcl. — metaccele. 



7ntpr. — metapore. 



pvl. — post velum. 



pvm. — post vermis, 



p. fix. — pontile flexure. 



plx. — plexus. 



rf.pl. — roof plate. 



rp. — ripa. 



Rg. au. — auditory region. 



supraflc. — supraflocculus . 



St. — stem. 



si. cl — saddle cleft. 



//.—tela. 



trans, s. — transitory sulci. 



uv. — uvula. 



vl. — velum. 



vm. tr. — vermian tract. 



vlv. — valvula. 



PLATE I. 



Fig. I. Left lateral aspect of the caudal three brain segments and myel of 

 an embryo pig 16 mm. long, No. 3337 (x 7.5). 



The specimen had been preserved in alcohol ; the cephalic two-thirds of the 

 cerebrum had been sliced off" by a previous inquirer. Shows, 



a. The large subspherical mesencephal. 



b. The contracted isthmus which has only about one half the diameter of 

 the mesencephal. 



c. The convex flaring walls and roof of the epencephal ; the roof arches 

 dorso-cephalad. 



d. The expanded metatela (roof or deckplate) and its lateral extension 

 caused by the pontile flexure. (This extension forms the caudal wall of the 

 adult parepicoele. See also Fig. 3.) 



e. The cranial flexure (head bend), saddle cleft, bend of the pons, and a 

 concavity in the metatela which later becomes a fold, the dorsal fold, Fig. 5. 



f. The left lateral proton or rudiment of the cerebellum, cbl. 



Fig. 2. Dorsal aspect of the same specimen. Shows, 



a. The ovoid appearance of the mesencephal at this period. 



b. The constricted isthmus. 



c. The elongated shield-shaped metatela and its lateral extensions which 

 later form a part of the paracoelian wall. 



d. The two lateral protons of the cerebellum. Compare Figs. 24 and 24 

 a, PI. in. 



e. The roof of the epencephal. Its extent is shown better in Figs. I 

 and 3. 



Fig. 2' Oblique view of the same specimen. Shows the same features as 

 Figs, I and 2, but gives a better idea of the isthmus and the cephalic termina- 

 tion of the metatela. 



