1 82 ANDREWS. [Vol. VII. 



The former view is strengthened by the appearances seen at 

 the pupil where, as on the left of Fig. 35, the clear not pig- 

 mented cells have filaments connecting, almost certainly, the 

 slender cells with the lens. 



It would thus appear that in this eye the retina is continuous 

 with the rods and with the lens, and the latter with the 

 cuticle.^ 



Unice ornata Andrews. 



Sections of the limited material of this species from North 

 Carolina suffice to show that the eye in this genus may agree 

 closely with that of Marphysa. 



The lens (Fig. 33) connects with the cuticle by a cylindrical 

 stalk, and is somewhat bilobed from the point of attachment of 

 this stalk. The pigment in the retina is like that in Marphysa 

 (is represented in the figure as nearly removed by acid), and is 

 also absent from a pupil-like area of clear cells along one side 

 of the lens, as in Fig. 35, of Marphysa. 



The axial part of the lens appears nearly liquid, is vacuolated 

 and shrunk : the denser peripheral part when shrunk away from 

 the retinal rods, as on the left of the figure, leaves clear fibrils 

 or strands passing in between the rods. These appear to be 

 the same as those seen in Nereis (Fig. 3), and also are identical, 

 as far as sections tell, with the lens filaments of Marphysa. 



Thus in depigmented sections of the retina (Fig. 37) the lens 

 is continued as large fibres passing between the granular proto- 

 plasm-like rods into the area depigmented. These fibres are 

 swollen and vacuolated just after leaving the lens, so that there 

 is formed a zone of rounded bodies suggesting minute nuclei, 

 but really comparable, I judge, to the vacuoles sometimes seen 

 in Nereis between rods and lens (Fig. 2). 



Another resemblance to Nereis is to be found in the presence 

 of an interrupted line, in depigmented sections, marking off the 

 rods from the cell bodies, being the limit of pigmentation. This 

 line is the expression of what seems a perforated membrane, 

 through which each large retinal cell continues as a rod, but 



1 An additional reason for associating the sipunculids with the annelids may be 

 found in the resemblance between the eyes of the two groups, as seen in comparing 

 the figures of the cephalic sense organs of Phymosoma as given by Shipley (^. J. 

 Mic. Sci.y 1890), with the above figures of the eyes of Marphysa (Fig. 34), especially. 



