398 The American Naturalist. [May, 
Fig. 4.—The triangular reticulations on the the ventral pos- 
terior margin of the shell. The petagonal and 
quadrangular cells, that sometimes occur above 
the marginal triangular cells are shown. (On 
nal. 
Fig. 5.—The circular eye spot with ake clear cells and 
the dark colored ocelli upon the face. (Original.) 
Fig. 6—The inferior antenna showing the spine in front, the 
two series of bulbous sete at the end and the en- 
circling rows of teeth. (Original.) 
Fig. 7—Short three-jointed ramus at the base and between 
the two large rami of the superior antenna, 
(Original.) 
Pn eS Te Sat atta a a eet See Ts cee 
gS A a ie te Twn sal 
