276 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 



Fig. 3. Transverse section of epithelium from anterior 

 intestinal region. x 300. 



Fig. 4. Longitudinal vertical section through brain 

 taken rather to one side of the median line, 

 x 45. 



Fig. 5. Transverse section through hinder region of 

 proboscis. The circular muscles and nervous 

 layer have both disappeared. x 120. 



Fig. 6. Transverse section through proboscis at its 

 widest — about the middle. x 80. 



Fig. 7. Longitudinal median section through anterior 

 end, shewing the relations of the proboscis to 

 the rhynchodseum and rhynchoccelom when 

 retracted. x 45. Somewhat schematic. 



Plate III. 



Fig. 1. Transverse section through so-called ciliated 

 canal of cerebral organ, shewing the seven 

 large external cells and the internal homo- 

 geneous cell layer all with crystalline ends 

 formed from fused cilia projecting into the 

 lumen. x 300. 



Fig. 2. Portion of intestinal epithelium, shewing the 

 circular refractive bodies enclosed in the 

 elongated ciliated cells, x 168. 



Fig. 3. Schematic longitudinal horizontal section 

 through the cerebral organ of a Heteronemer- 

 tean. (After Burger). 



Fig. 4. Section through eye just anterior to the entry 

 of the nerve into the pigmentary layer, x 240. 



Fig. 5. Section through blind end of an excretory 

 tubule (left portion), shewing elongated cilia, 

 x 300. 



