108 Journal of Comparative Neurology 



metapore is to be found in the early embryo which closes near 

 the end of fetal life. 



5. The inter-optic lobes are highly developed in turtles. 

 In Chelydra they show externally as small lobes caudad of the 

 base of the pregemina, but in other forms, as pointed out by 

 Spitzka, they exist only as large nidi. 



6. In the roof of the diencephal of the turtle three evagina- 

 tions exist. The "velum transversum" is only slightly developed 

 and from it no plexus is formed as is the case in Amphibia. 



7. The plexuses of the regions of the portae and aula are 

 all prosencephalic in origin. 



8. The crista is present in all forms examined. In Chelone 

 tnidas only did it possess a true nervous structure. Its morph- 

 ological value was not ascertained. 



The foregoing paper was prepared in the laboratories of the 

 Anatomical Department of the Cornell University. To the kind 

 assistance of the members of that Department, and especially to 

 the discussions in the Neurological Conferences, I owe a great 

 part of whatever of value the paper contains. 



BIBLIOGRAPHY. 



In preparing this bibliography no attempt has been made to make it com- 

 plete. Titles are given of such works only as were consulted in the prepara- 

 tion of this paper, though many of these works are not directly referred to. 



1. Agassiz, L., 1857. Contributions to the Natural History of the U.S., Part 



2, North American Testudianata, 4to, 237-452. 



2. Same, Part 3, Embryology of the Turtle, 452-640. 



3. Ahlborn, F., 1883. Untersuchungen iiber das Gehirn der Petromyzon- 



ten. Zeit. wiss. Zool., XXXIX, 191-294. 



4. Beard, J., 1888. The Parietal Eye in the Cyclostome Fishes. Quart. 



Jour. Micro. XXIX, 55-73. 



5. Bellonci, J., 1881. Ueber den Ursprung des Nervus opticus, und den 



feineren Bau des Tectum Opticum der Knochenfische. Zeit. wiss. Zool 

 XXXV, 23.29. 



6. 1888. Ueber die centralen Endigung der Nervus Opticus bei den 



Vertebraten. Zeit. wiss. Zool., XLVII, 1-46. 



7. Beraneck, Ed., 1883. Recherches sur le developpement des nerfs craniens 



chez les lezards. Recueil Zool. Suisse, I, 519-603. 



8. 1887. Ueber das Parietalauge der Reptilien. Jenaische Zeit. XXI, 



374-51 1- 



o, . 1892. Sur le nerf parietal et la morphologie du troisieme oeil des 



Vertebres. Anat. Anz. VII, 674-687. 



