208 



Fig. 09. Longitudinal section through the eye. The 

 optic ganglion is also shown. x 12. 



Fig. 70. Enlarged drawing of two of the ommatidia 

 from the previous figure. x 450. 



Fig. 71. Transverse section across one of the ommatidia 

 in the previous figure, through the rhabdomo 

 and retinulae. x 1000. 



Fig. 12. Transverse section across one of the ommatidia 

 in the previous figure, through the vitrella and 

 the pigment cells. x 1000. 



Fig. 73. Surface view of the cornea, showing one of the 

 corneal facets. x 750. 



Fig. 74. Olfactory seta taken from the exopodite of the 

 first antenna. x 1100. 



Fig. 75. Auditory seta (" hooked seta ") from the audi- 

 tory sac of the first antenna, x 400. 



Fig. 70. Auditory seta (" group seta ") from the auditory 

 sac of the first antenna. x 300. 



Plate XII. 



Fig. 77. reproductive system of a fairly mature female, 



showing the double ovary, the spermathecae 



and the oviducts. x 1. 

 Fig. 78. Reproductive system of an immature male, 



showing the paired testes, the vas deferens and 



the ejaculatory duct. The fore-gut is also 



shown in position. x 2. 

 Fig. 79. Section through an almost ripe ovary, showing 



the eggs filled with yolk granules. The 



details are only inserted in one egg. x 190. 

 Fig. 80. A very earl}* stage in the development of the 



embryo, attached to a seta of an endopodite 



of a female pleopod. This drawing shows the 



method of attachment. x 50. 

 Fig. 81. Ripe spermatozoon, showing the two processes. 



Taken from spermatheca of female, x 1400. 

 Fig. 82. Some of the epithelial cells of the bladder of the 



excretory system. The striated nature of the 



protoplasm is shown. x 050. 



