66 



KHKDKHICK TIIA'KV AND U'THKR F. WAHRKX 



marked paraphyseal evagination, a velum trans versum, a dorsal 

 sac, a commissTira habenularis, and a single thick-walled anlage of 

 the pineal body whose apex is directed cephalad. The most 

 caudal structure in the pineal region is the posterior commissure. 



D.s 



Pf 





l'"\. '>'' Keconst met inn MI'. -i :!() mm. embryo of Thalassoc-liclys curctta. 

 7,x.. l:iinin:i tci'iiiinalis ; /'/'., parajiliysis; I'., velum t raiisvcrsum ; Ds., dorsal 

 sac; f'ti., CMniiinissiira lialicnularis ; !'<>., cpiphysis; Cp., posterior commissure; A'.. 



Kat like pocket 



