I08 HAROLD HEATH. 



Explanation of Plate I. 



Fig. I. Ctenosailum hawaiiense with left half of the pseudo-pallium removed. 

 c, cerebral ganglia; k, kidney ; /, liver ; o, oesophagus; /, papillae arising from body 

 wall ; sg, salivary gland ; st, stomach. 



Fig. 2. Cyst in starfish arm produced by parasite. 



Fig. 3. Two types of cells of gastric epithelium. 



Fig. 4. Outlet of salivary gland ( ^) into reservoir (^). 



Fig. 5. The single tooth of the radula with salivary ducts opening on each side. 



Fig. 6. Cuticular teeth guarding the opening into space between body and pseudo- 

 pallium. 



Fig. 7. Papillate cuticle, from ventral surface of body, traversed by nerve fibers. 



Fig, 8. C. hawaiiense, entire animal, ventral view. 



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