334 S. WATASE. 



ganglion cell of Limulus nor to the ''hyaline cell " of Serolis can be 

 found. The sensory element of the oniniatidiuni is represented by 

 the retinulae (HI) only. 



Fig. 7-i. — Liiniduii. Diagram of the compound eye of Limulus, 

 the black, heavy line representing the ectoderm and each depression 

 in this layer corresponding to an ommatidium. 



Fig. 75.— Serolis. In the same way as the above, the eye of Serolis 

 may be represented by a series of folds. 



Fig. 76.—Jfoionecfa. 



Fig. 77. — Agrion (Larva). 



Fig. 78. — Branchipus. 



Fig. l^.—Cambarus. 



Fig. 80. — Penacus. 



Fig. SL—Lnci/er. 



