264 



ME. F. E. BEDDAED OX ANNELIDS 



On the Structure of the Eyes in Chloeia merguiensis. 



So far as I am aware, there is no description of the minute 

 structure of the eyes in Chloeia, or, indeed, in any of the Amphi- 

 nomidae. The excellent state of preservation of the specimens 

 of Chloeia merguiensis has enabled me to contribute some obser- 

 vations on the eyes of this species to what is already known 

 of the structure of the Annelid eye. This worm possesses, in 

 common with other Amphinomidse, two pairs of eyes situated 

 one in front of the other ; these are recognizable to the naked 

 eye as four black spots upon the procephalic lobe. 



The first point to which I directed my attention was to ascer- 

 tain w r hether or not there was any difference in structure between 

 the anterior and posterior pairs, as there is, for example, between 

 the eyes of Nereis cultrifera*. I did not, however, detect any 

 differences of a similar nature, or of any kind whatsoever between 

 the eyes of either pair t. 



The following description, with the reservation stated in the 

 footnote, applies to both pairs. 



The retina (fig. 8, r) consists of a single row of tall narrow cells, 

 as in other Annelids, which terminate in long rods (n), the struc- 

 ture of which, owing to their excessive slenderness, I am unable to 

 describe. The retinal cells are for the most part rather longer 

 t han their rods ; and appear to be all deeply pigmented, the colour 

 of the pigment being black. Curiously enough, a small region of 

 the retina on one side of the eye has an orange-coloured pigment 

 deposited in the retinal cells ; this is evidently not an accidental 

 variation, as I found that in all four eyes of the single specimen, 

 which I examined microscopically, the same region of the eye 

 presented an exactly similar condition of the retinal pigment. 



The cells of the retinal layer are not, however, equally pig- 

 mented throughout. The pigmented area is about half the extent 

 of the retinal area, the lower half of these cells being entirely free 

 from pigment ; the pigment also appeared to be largely extrinsic, 

 though a portion of it is certainly intrinsic, i. e. within the 

 substance of the retinal cells. It is therefore probable that there 

 :i Chloeia a resemblance to Nereis, in which Annelid Carriere 



* Carrirre, ' J)i<: Schorgano dor Thiore,' Mimclien u. Leipzig, 1885, p. 31. 



I hould Hate, however, that I did not obferre very clearly the relation! of 

 the lens in the firnt pair. 



