PARKER. — Compound Eyes in Crustaceans. 
PLATE III. 
Pontella. 
Figs. 20-29. A complete series of ten consecutive sections through the right and 
left retinas in planes parallel to the horizontal plane of the animal. 
The sections are viewed from their dorsal faces. Figure 20 represents 
the most ventral section; Figure 29, the most dorsal. The plane of 
Figure 25 is approximately indicated by the incomplete dotted line 
mu. con.in Figure 18 (Plate II.). In the sections on the present plate 
the different bodies in the left retina have been designated by appropri- 
ate letters and figures. The eight rhabdomeres have been indicated 
simply by numbers; the same number always refers to the same 
rhabdomere. For the sake of distinction, the two cone cells have 
been marked cl. con. I and cl. con. 2. Some of the nerve fibres 
(n. for. 7 and n. fbr. 8) have been numbered in reference to the par- 
ticular rhabdomeres with which they are associated. X 400. 
