68 Journal of Comparative Neurology. 



enough to tear an opening entirely through the cuticula when 

 the latter is removed. Since the cuticula in the palps is much 

 thinner than that over the body it may be that the peripheral 

 processes of the anchoring cells in the former region extend 

 entirely through the inner cuticular layer, into the outer layer, 

 or it may be that there is a more intimate connection between 

 the two layers of cuticula themselves than between those of the 

 the body. Either supposition would account for the fact that 

 these openings are so often found in these two appendages and 

 so rarely in the body. As only a very few anchoring cells were 

 stained in the palps, I was not able to decide this question 

 by actual study. In the tentacles there are no muscles, but a 

 number of very coarse connective tissue strands pass from the 

 base of the tentacles toward the cuticula and these strands may 

 be basal processes of anchoring cells, processes connected with 

 muscles at the base of the tentacles. When the cuticula is re- 

 moved from the ventral surface of Nereis, there is sometimes 

 found in it large circular openings in those places to which the 

 ventral oblique muscles pass ; these openings, it seems to me, 

 are also due to the firm attachment of groups of anchoring cells. 



I have been able to examine only the head and first meta- 

 mere for these anchoring cells. In these regions, they are 

 present in the epidermis wherever muscle-fibers pass to or into 

 the latter. They are especially numerous in the epidermis of 

 the grooves which pass across the prostomium and to which 

 large numbers of muscle-fibers are attached. I have found 

 them at the bases of the cephalic appendages, at the insertion 

 of the muscles moving these appendages, and at the point of in- 

 sertion of the ventral oblique muscles of the first metamere. 



I have found no description of cells exactly like these 

 anchoring cells of Nereis but I have found two references to 

 epidermal cells which may be, I think, such cells. Andrews 

 ('92) after describing the apparent connection of the retinal 

 cells in the eye of Eunice with the lens itself states that : 

 "Some views of the common epidermis of the head lead one 

 to infer that here also the attenuated cells amongst the larger 

 epidermal cells have a close connection with the cuticula like 



