PLATE 43. 



CESTRACIONTIDAE, CARCHARINIDAE, and SQUALIDAE. 



Fig. 1. Cestbacion TiBDRO (Page 160). Fig. 2-3. Ce.stracion zygaena (Page 1.57). Fig. 4-5. 

 Carcharinus platyodon (Page 126). Fig. G-S. Galeocebdo arcticus (Page 148). Fig. 9-10. 

 Squalus acanthias (Page 192). 



1. Dorsal view of brain. M. C. Z. 1292. 



2. Dor.sal view of brain. M. C. Z. 1291. 



3. Ventral view of brain. 



4. Dorsal view of brain. 



5. Nasal sac, bisected. 



6. Dorsal view of brain. M. C. Z. 1288. 



7. Ventral view of brain. 



8. Lateral view of brain. 



9. Dorsal view of brain. M. C. Z. 1298. 

 10. Ventral view of brain. 



From tlie brain of tlie Carcliaridao, Plates 40 and 41, tliere was in the Vulpcculidae, Plate 42, a 

 marked increase in the plication of tlie hind brain with a less considerable one in the size of the fore brain. 

 In Plato 43, the much greater advance of the Cestraciontidae is seen both in the volume of the fore brain 

 and the complexity of the hind brain; these are more advanced in the Cestraciontidae than in the 

 Carcharinidae, the nearest alHes, for instances see fig. 4, Carcharinus platyodon, and figs. 6-8, Galcoccrdo 

 arclicus. Tliat the archaic family Squalidae is much lower in rank is indicated by the smooth hind 

 brain and the smaller amount of the fore brain. 



.J 



