35 



Fig. -1 Transverse section of epithelinm from anterior 



intestinal region. x .'JOO. 

 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 muscdes and nervous 



layer have both disappeared. x 120. 

 Fig. 6. Transverse section thioTigh ])roboscis at its 



widest — about the middle. x 80. 

 Fig. 7. Longitudinal median section through anterior 



end, shewing the relations of the proboscis to. 



the rhynchodiBum and rliynchocceloiu when 



retracted. x 45. Somewhat schematic. 



Plate IIL 



Fij;. 1. Transveise section through so-called ciliated 

 canal of cerebral or^'an, sliewinef 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 ."JOO. 



Fig. 2. Portion of intestinal epithelium, shewing the 

 circular refractive l)odies enclosed in the 

 elongated ciliated cells. x 108. 



Fig. ^. Schematic longitudinal horizontal section 

 through the cerebral organ of a Heteronemer- 

 tean. (After Biirger). 



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 poition), shewing elongated cilia, 

 x 300. 



