Parker. — Compound Eyes in Crustaceans. 



PLATE I. 



Gammarus. 



Fig. 1. A section of the right eye in a plane transverse to the cliief 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 tlie numbers of the six following figures 



of transverse sections, and mark the levels at vvliich 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 througli the proximal portion of the cone and 



tlirough the adjoining retinular cells. X 475. 

 ■' 6. A transverse section througli the retinula in the region of the rhabdome. 



X 475. 

 -' 7. A transverse section through the retinular cells somewhat proximal to 



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 Miiller's fluid. Not stained. X 475. 

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



X 475. 



