Parker. — Compound Eyes in Crustaceans. 



PLATE I. 



Gammarus. 



Fig. 1. A section of the right eye in a plane transverse to the chief axis of the 

 body and through the central part of the retina. X 115. 



2. A section lengthwise of an ommatidium. The numbers at the left of 



the figure correspond to the numbers of the six following figures 

 of transverse sections, and mark the levels at which the latter were 

 taken. X 475. 



3. A transverse section in the plane of the corneal hypodermis. X 475. 



4. A transverse section through the distal ends of the retinular cells and 

 cone. X 475. 



5. A transverse section through the proximal portion of the cone and 

 through the adjoining retinular cells. X 475. 



6. A transverse section through the retinula in the region of the rhabdome. 

 X 475. 



7. A transverse section through the retinular cells somewhat proximal tp 

 the basement membrane. X 475. 



8. A transverse section through a single retinular cell in the region of its 

 nucleus. X 475. 



9. The proximal portion of a retinular cell viewed from the side. (Compare 



Fig. 2.) Isolated in Muller's fluid. Not stained. X 475. 



10. A cone isolated in Muller's fluid and viewed from the side. Not stained. 

 X 475. 



