No. 2.] COMPOUND EYES OF ANNELIDS. 299 



Figs. 20-22. Dasychone conspersa. 



FlG. 20. Transverse section of outer part of a branchial stem cutting across a 

 pair of eyes. 2 • D. 



Fig. 21. Portion of radial section of depigmented eye, inclusions or cuticular 

 ingrowthSj axial parts and nuclei of sensory cells, with nuclei of pigment cells. 8 • 4. 



Fig. 22. Isolated refracting bodies or cuticular ingrowths, in two cases attached 

 to cuticle. 8 • 4. 



Figs. 23-27. Hypsicomus. 



Fig. 23. Transverse section of outer part of a branchial stem, an eye cut where 

 in contact with cuticle on one side, and where buried amongst epidermal cells on the 

 other side. 2 • D. 



Fig. 24. Section vertical to epidermis and parallel to long axis of an eye. Hsema- 

 toxylin. 8 • 4. 



Fig. 25. Inner end of such a section as Fig. 24, but depigmented. A single 

 terminal cell, pigmented, contains the clear refracting spherule, and abuts against 

 the truncated end of the refracting cuticular cone. 8 ■ 4. 



Fig. 26. Section at right angles to the above, and passing across the apex of the 

 conical, cuticular, refracting body and the three surrounding pigmented cells. 8- 4. 



Fig. 27. One of the refracting cones isolated with a fragment of cuticle con- 

 tinuous with its base. 8 • 4. 



Fig. 28. Hydroides dianthns ; transverse section of outer part of branchial stem, 

 showing two nerves in the angles, but no eyes. 2 • D. 



