24 
PEOPESSOR H. N, MOSELEY. 
sbaded. A lower part of t.be lateral face of one of thè middle sbells is covered 
by minute eye specks. b ò. Calcareous plates of thè girdle. 
Fig. 7. — Outline of thè entire specimen of Enoplochiton incisus of 
life size, viewed from thè side, a. Area included by a dotted line, showing 
thè situation of thè part magnified in Fig. 6. 
Fig. 8. — A small portion of thè surface marked a in Fig. 6, more highly 
magnified. d. Eyes. a. Megalopores. c. Area, stili more highly magnified 
in Fig. 9. 
Fig. 9. — Area marked c in Fig. 8, further enlarged. a. Megalopores. 
h. Micropores. 
Fig. io. — Schemalic representation of thè form and arrangement of thè 
organs of touch in thè shell of Chiton magni ficus, as seen after decalci- 
fication, in a section vertical to thè shell surface. a. Megalsesthetes. b. Mi- 
craesthetes, d. Stem of a megalsesthetes. e e. Maio soft tissue strands. 
PLA.TE V. 
Fig. 1. — Anterior shell of Tonicia elegans; external view, showing 
thè arrangement of thè eyes in radiating lines. 
Fig. 2. — Enlarged view of two rows of eyes from thè above, only partially 
shaded. The eyes are sunk in a series of slight depressions, forming a partial 
groove on thè surface of thè shell. 
Fig. 3. — Portion of thè surface of thè same, stili more enlarged. (t. Mega- 
lopores. b. Micropores. 
Fig. 4. — Lateral view of one of thè 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. Incisurse marginalis. 
Fig. 5.— Part of thè surface of thè same, hearing thè scattered eyes much 
enlarged. a. Macropores. d. Eye. c. Avesi, shown stili more enlarged in 
Fig. 6. 
Fig. 6. — a. Megalopore. b. Micropore. 
Fig. 7. — Anterior shell of thè same species of Onithochiton partially 
shaded, showing thè more or less regalar radiai rows of eyes. 
Fig. 8. — Schematic representation of thè tactile organs and an eye of 
Corephium aculeatum, as seen in a section vertical to thè surface in 
decalcified specimens, excepting that thè calcareons cornea is bere retained. 
a. Free end of a megaleesthete, projecting at thè shell surface. b. Micrsesthete. 
b' b'. Micraesthetes supplied by olfsets of thè optic nerve, which perforate 
thè iris to reach thè surface. d. Base of megalaesthete. e. Main nerve 
brandi, k. Pigmented eye- capsule and cavity of eye-capsule. ?i. Optic 
nerve. k. Iris. /. Calcareous cornea. 
