222 Journal of Comparative Neurology. 



The following is a summary of the results obtained from a 

 study of these bodies. 



1. The sensory nervous system of Phascolosoma gouldii 

 is to be found entirely in the epidermal organs distributed 

 abundantly throughout the body of the worm and the nerve 

 fibers connecting them with the central nervous system. 



2. These epidermal bodies may be grouped into four 

 classes, two of which contain gland cells, the other two being 

 non-glandular. The two types of glandular organs may be 

 readily distinguished by the presence or absence of intracellular 

 canals in the gland cells, while the two types of non-glandular 

 organs are to be distinguished by the possession in one case of 

 a bulb-like structure projecting above the general level of the 

 cuticula. 



3. All four classes of the epidermal organs possess sen- 

 sory cells. 



4. Nerve fibers are never found in continuity with the 

 gland cells of either type of glandular organ, as has been sev- 

 eral times asserted by different investigators. 



5. The sensory cells of all these organs are bipolar, the 

 cell body in the non-glandular organs being larger than that in 

 the glandular organs. 



6. Each of the peripheral processes of the sensory cells 

 ends in a delicate sensory hair which in some cases at least is 

 prolonged beyond the surface of the cuticula. In one case only, 

 the glandular organs of the first type, the exact form of the per- 

 ipheral ending was not made out. 



7. The central processes of all these sensory cells enter 

 the large nerves passing to the ventral nerve cord. 



8. One type of glandular organ possesses a remarkable 

 structure consisting of a communicating set of intracellular 

 canals, each canal leading from an otherwise closed pouch. This 

 pouch is surrounded by a zone of radiating threads. All these 

 communicating canals finally open to the surface through a 

 common duct. 



9. The intracellular sacks belonging to this type of glan- 

 dular organ are reservoirs for the secretion from the gland cells 



