EXPLANATION OF PLATE 46. 
73 
Fig. 11. Anterior segment of the left Eye of Fig. 9, still 
more highly magnified, to shew the circular lenses 
set in their respective margins, each surrounded by 
six minute tubercles. (Original.) 
Fig. IF. Magnified view of a portion of the eye of Caly- 
mene macrophthalmus. (Hoeninghaus.) 
Fig. 12. Under surface of the anterior portion of the 
shield of Asaphus platycephalus, from Lake Huron. 
An unique specimen, shewing at f. an entrance to 
the stomach, analogous to that in recent Crabs. 
See Geol. Trans. N. S. Vol. i. PI. 27. (Stokes.) 
Plate 46. V. I. p. 389 et seq. 
Figs. 1. 2. 3. Calymene Blumenbachii, from the Tran- 
sition Lime-stone of Dudley, a. The shield cover- 
ing the head. a'. Lateral portion of the shield, 
separated by a suture from a . ; the central part of 
this suture forms the lateral Margin, or Rim of the 
cavity of the Eye. This Margin is composed of 
two parts, united to receive the Lens, like the rims 
that enclose the edges of the glasses, in a pair of 
Spectacles. The Lens has usually fallen out from 
the Eyes of fossils of this species, as often happens 
after death in the Eyes of the recent (xrapsus pic- 
tus, and also in the common Lobster, b. The Eye. 
c. The dorsal portion, composed of articulating 
plates, that move on one another like the plates of 
a Lobster’s tail. d. The tail. 
Fig. 1. Side view of the Animal rolled up like an Onis- 
cus. (Scharf.) 
Fig. 2. View of the back of the Animal expanded for 
swimming; the Tail d, is composed of plates that 
had no moveable articulations. (Original.) 
Fig. 3. Front view of the same Animal rolled up ; the 
