288 ANDREWS. [Vol. V. 



large, spherical eye, only one side of this eye being free from 

 the very numerous crystalline cones. The pigment ensheath- 

 ing the cones is violet. In the figure we note each element of 

 the eye is a radiating, dark red-brown, cell-like body, bearing a 

 yellow, clear mass in its peripheral end next the cuticle; these, 

 elements are separated by considerable intervals. Here, also, 

 experiment proved the animal very sensitive to light and shadow, 

 as in the above case. 



In Vermilia infundibulum there are at least 220 separate 

 ocelli upon the outer side of each branchia, about 11,000 eyes 

 in all ! Each is a pear-shaped, crystalline body 20 [x. long, im- 

 bedded in red pigment, which appears to adhere especially to 

 its centrally placed apex. 



Some eight years later J. Chatin (5) gave figures and descrip- 

 tions of the eyes of several of these Annelids, and attempted to 

 compare them closely with the compound eyes of Arthropods. 



In Psygmobranchus protensis, Phil., he finds an elongated, 

 pyramidal mass of red-orange color, having a clear, crystalline 

 body in its outer, basal end, next the cuticle. 



In Protula intestinum, Lamb., the eye is made up of two such 

 elements, with bright red pigment, while several species of 

 Eupomatus have ten or twelve such in each eye. In Dasyclione 

 bombyx, Daly ell, the animal first mentioned by Daly ell, as above 

 stated, there are three or four elements in each eye ; each is sep- 

 arable as a pigmented, pyramidal mass, with a clear, crystalline 

 body at its outer, basal end. Kolliker, it is to be remembered, 

 found fifteen to eighteen clear bodies in the eye of this animal, 

 but Chatin appears to indicate only the number seen in section. 



The pigmented spots upon the body are found by Chatin to 

 contain no refractive bodies, and hence are not to be regarded 

 as eyes. 



In D. lucullana Delle Chiaje, however, there are two pigment 

 spots upon each somite, covered by a modified cuticle, and con- 

 taining a number of elements having a prismatic, refracting part 

 set in a sheath of pigment, and drawn out into a filament at 

 the apex. 



The branchial eyes of this species have as many as eight 

 elements, such as were described for D. bombyx. 



Finally, in Vermilia clavigera, Phil., the branchial eyes present 

 the bright, shining appearance of the eyes of Pecten, and are 



