PLATE VIL: 
Fic. 1 — Enlargement of outer surface of gill. 
g. p. Gill plates. c. i. Cilia. 
ch. Chitinous rods. : 
Fic. 2.— Enlargement of capillaries of gills. 
Fic. 3.— Enlargement of veins of mantle. 
Fic. 4.— Showing specimen with mantle removed. 
a. a. Anterior adductor muscle. r. Rectum. 
a, r. Anterior retractor muscle. a, Anus. 
p. p. Protractor pedis muscle. p. a. Posterior adductor. 
m. Mouth. p. r. Posterior retractor. 
1. p. Labial palpi. p. Pericardium. 
f, Foot. v. Ventricle. 
b. c. Branchial chamber. au. Auricle. 
t. Tentacles of inhalent-siphon. m. Mantle. 
c. c. Cloacal chamber. g. Gill. 
Fie 5.— Showing the mantle and gills thrown back exposing the foot, body 
and labial palpi. 
m. Mantle. o. g. Outer gill. 
mo. Mouth. b. c. Branchial cavity. 
1. p. Labial palpi. t. Tentacles of inhalent siphon. 
f. Foot. op. Opening through the gill for 
b. Body. passage of the body. 
i, g. Inner gill. 
