18 ARKIV FÖR ZOOLOGI. BAND 8. N:0 25. 



Figs. 18 — 19. Scheme of the nervous systems of Ptisanula (Fig. 18) 

 and Biapliana (Fig. 19). bucc buccal ganglia, c cerebral 

 ganglia, gl salivary glands, int intestine, m mouth, oc eyes. 

 ol tentacular ganglia and the diffuse olfactory layer, prd 

 pedal ganglia, ph pharynx, pl pleural ganglia, sub subin- 

 testinal ganglion, sup supraintestinal ganglion, vise visceral 

 ganglion. 



Tryckt den 10 februari 1914. 



Uppsala 1914. Almqvist & Wiksells Boktryckeri- A.-B. 



