d.com.~-gii§ 

 v.com 



pt. hrn. 



bm. re. pft- ps. pfi>'. 



rh.( 



St. intd. A 



•?• Pf- P^- ect. 



Fig. i6i. 



Fig. i6i. Cerebratulus fusciis. Dorsal view of young transparent form, x 7. 

 After Burger, brn. cerebral ganglia; c.p. cephalic pit, a lateral slit in which is 

 situated the cerebral organ; d.com. dorsal and v. com. ventral commissures of 

 cerebral ganglia ; la.v. lateral vessel ; M. position of mouth seen through the 

 body; ph. proboscis; p.al. pouches of alimentary canal; pt.hrn. posterior part 

 of cerebral ganglion; re. rhynchocoel; rh. rhynchodaeum ; st. stomach. 

 Fig. 162. A, Longitudinal vertical section of a metanemertine to show the 

 relation of the various cavities. After Benham. brn. cerebral ganglia; int. 

 intestine; int.d. coecum; pb. proboscis; pb.' solid non-eversible part of the 

 former, attached to the proboscis sheath and acting as a retractor muscle ; 

 ps. proboscis sheath; re. rhynchocoel; rh. rhynchodaeum; std. stomodaeum; 

 St. stomach. B, Transverse section of a palaeonemertine, passing through a 

 pouch of the intestine on the right and an ovary on the left. After Coe. 

 eet. ectoderm; l.v. lateral blood vessel; l.n. lateral nerve; m.e. circular 

 muscles; m.l. longitudinal muscles; ov. ovary; p.al. pouch of intestine; 

 par. parenchyma. Gther letters as above. C, Proboscis of a metanemertine 

 to show the diaphragm and the stylets sy. and sy.' After Bresslau. 



