58 
PEOFESSOB H. N. MOSELEY. 
shaded. A lower part of the lateral face of one of the middle shells is covered 
by minute eye specks, b b. Calcareous plates of the girdle. 
Fig. 7- — Outline of the entire specimen of Enoplochiton incisus of 
life size, viewed from the side. a. Area included by a dotted line, showing 
the situation of the part magnified in Fig. 6. 
Fig. 5. — A small portion of the surface marked a in Fig. 6, more highly 
magnified, d. Eyes. a. Megalopores. c. Area, still more highly magnified 
in Fig. 9. 
Fig. 9. — Area marked c in Fig. 8, further enlarged, a. Megalopores. 
b. Micropores. 
Fig. 10. — Schematic representation of the form and arrangement of the 
organs of touch in the shell of Chiton magnificus, as seen after decalci- 
fication, in a section vertical to the shell surface, a. Megalaesthetes. b. Mi- 
craesthetes. d. Stem of a megalaesthetes. e e. Main soft tissue strands. 
PLA.TE Y. 
Fig. 1. — Anterior shell of Tonicia elegans; external view, showing 
the arrangement of the eyes in radiating lines. 
Fig. 2. — Enlarged view of two rows of eyes from the above, only partially 
shaded. The eyes are sunk in a series of slight depressions, forming a partial 
groove on the surface of the shell. 
Fig. 3. — Portion of the surface of the same, still more enlarged, a. Mega- 
lopores. b. Micropores. 
Fig. 4. — Lateral view of one of the middle cells of a species of Onitho. 
chiton. The tegmentum has a series of eyes upon it, which commences as a 
single row superiorly and broadens out into a scattered group inferiorly. 
t. Tegmentum, a. Articulamentum. b. Incisurae marginalis. 
Fig. 5. — Part of the surface of the same, bearing the scattered eyes much 
enlarged, a. Macropores, d. Eye. c. Area, shown still more enlarged in 
Fig. 6. 
Fig. 6. — a. Megalopore. b. Micropore. 
Fig. 7- — Anterior shell of the same species of Onithochiton partially 
shaded, showing the more or less regular radial rows of eyes. 
Fig. 8. — Schematic representation L of the tactile organs and an eye of 
Corephium aculeatum, as seen in a section vertical to the surface in 
decalcified specimens, excepting that the calcareous cornea is here retained. 
a. Free end of a megalaesthete, projecting at the shell surface, b. Micraesthete. 
b' b'. Micraesthetes supplied by offsets of the optic nerve, which perforate 
the iris to reach the surface, d. Base of megalaesthete. e. Main nerve 
branch, k. Pigmented eye-capsule and cavity of eye-capsule, n. Optic 
nerve, h. Iris. /. Calcareous cornea. 
