Thompson, Brains of Cerebratulus. 



^57 



Fig.l 



AH figures refer to Cerebratulus lacteus, and are drawn at the level of the stage with the Zeiss camera 

 lucida, and with Zeiss lenses, the combinations of which are given with each figure. The plates have 

 been reduced to about two-thirds of the original size. 



Fig. I. A reconstruction of the brain from a series of transverse sections. Obj. AA, oc. 2, tube 

 length 160 mm. mdn, median dorsal nerve; prn, proboscis nerve; DL, dorsal lobe; FL, ventral lobe;«i, 

 neurocord cell of the first pair; jBA^, oesophageal nerve; DC, dorsal commissure; Fi, first ventral com- 

 missure; 2-14, 2d to 14th ventral commissures; a, cellular sheath. 



