a manual of zoology phylum chordata 353 the spinal cord is similar in essential respects in all three examples it is a cylindrical cord of nenx matter having running along the middle of its dorsal surface a fissure the vj jjoz fig 219 dorsal view of the brain of scyllium canicula the posterior division of the brain is the medulla oblongata nh on the dorsal surface of which is shown one of the central ventricles f rho the large cerebellum hh nearly covers the optic lobes mh the diencephalon zh shows in the middle one of the central ventricles and the place of attachm pg3yr5.jpg from cord bank加微信号ivf2024rokldc miskawaang4n View Photo