1 98 ANDREWS. [Vol. VII. 



pigment in these cells lies where the rod and cell body meet, 

 but leaves a central axial region of the cell clear, as in Nereis. 



No nuclei could be found in these large retinal cells in the 

 imperfect material at hand, but nuclei are plainly shown in this 

 region in the figures given by Graff (ll). 



We may thus regard the eye of the Tomopteridae, provision- 

 ally at least, as intermediate between that of the Spionidae and 

 the more complex forms met with in the Nereidae, etc. 



The simple character of the eyes in this family of pelagic 

 annelids, as compared with the perfect forms found in the free- 

 swimming Alciopidae, Nereidae, and Syllidae, may possibly be 

 connected with the great transparency of the body in Tomop- 

 teris, that rendering a projecting convex eye less necessary. 



Opheliad^. 



Here again I am indebted to Professor Patten for specimens 

 of Polyophthalmus from Naples. 



The eyes lie in the brain as masses of pigment surrounding, 

 in part, a clear body separable into a denser more easily stained 

 zone, next the pigment, and a central lens at the mouth of the 

 pigment cup and not separated from the surrounding brain sub- 

 stance. 



These very imperfect observations would thus reduce the eye 

 to a structure like that of Spio (Fig. 71). 



Meyer (12) has found greater complexity in the refracting and 

 corneal part of the eye in P. pictus, while Lessona (13) found 

 merely a bifid lens mass in a pigmented cup. 



The " lateral eyes " of Polyophthalmus, so often referred to, 

 are not, judging from my sections, eyes at all, but peculiar epi- 

 dermal organs composed largely of gland-like tubular bodies, 

 parts of a system of epidermal tubules. 



From the notice in the work of Albert (14), it appears that 

 Meyer has abandoned the interpretation of these organs as eyes, 

 and inclines to regard them as possibly light organs. 



Another form of reduced or degenerate eye has been discov- 

 ered in the Capitellidae, by Eisig (15). The eyes are here col- 

 lections of scattered pigment cells. In the adult these are in 

 the brain, but in the young may be in the epidermis. 



Toward the cuticle the cell has a clear lens-like part in which 



