THE MORPHOLOGY OF THE PINEAL REGION 



IN TELEOSTS^ 



ROBERT J. TERRY 



From the Department of Comparative Anatomy, Harvard Medica' School 



TWENTY TEXT FIGURES 



CONTENTS 



Introduction 321 



I. Description - 324 



Opsanustau: 



Embrj'os of 11 mm. in length 324 



Embryos of S mm. in length 332 



Embryos of 5 mm. in length 335 



Embryos of 3.5 mm. in length 336 



Larvae of 15 mm 338 



Larvae of 19 mm 339 



Adult Opsanus 342 



II. Discussion 344 



Morphological divisions of the fore-brain roof 344 



Epiphysis 347 



Posterior commissure 349 



Superior commissure 350 



Post-velar arch 351 



Velum transversum 352 



Paraphysis 353 



III. Conclusions 354 



Bibliography 356 



Reference letters 359 



Introduction 



In 1901 Minot published an account of the morphology of the 

 pineal region in which it was shown that the characteristic struc- 

 tures included therein had their beginnings in constant well-defined 

 divisions of the fore-brain roof. These subdivisions constitute a 

 succession of arches and intervening projections into the ven- 

 tricle, and in Acanthias are recognizable in embryos of 11.5 mm. 



JOflRNAI, OP MOBPHOIjOGT, VOL. 21, NO. 3 



