ANOMIID-, 173 
truncated, ending in a disk, from the depressed centre of which issues a 
small, cylindrical tendon terminating in a small, oviform, fleshy mass. 
Shell irregular, attached by the right valve, radiately ribbed, spiny, or 
foliaceous ; hinge with two strong teeth. 
Genus, PLICATULA—Lamark. 
Shell inequivalve, plicate, irregular, attached by the beak of the 
right valve ; beaks not eared ; hinge with two strong diverging cardinal 
teeth in each valve, with an intermediate cartilage pit. 
P. novee-zealandie, Sowerby in Reeve’s Conch. Ic., ft. Shell 
thin, white, depressed, leafy at the sides; plaits numerous, obtuse, here 
and there divided, dentiform at the margin (Sowerby). 
The ribs are so divergent, that those near the dorsal margin are at 
right angles with the central. 
New Zealand. (British Museum). 
FAMILY—ANOMIID. 
Mouth with narrow, plain lips, confluent with the gills; palps 
obsolete. Mantle wide open, except at the hinge, with a double pen- 
dent ‘margin, fringed with short cirri ; no ocelli; gills two on each side, 
unsymmetrical, united posteriorly, and suspended by two falciform 
membranes ; outer gill lamina, furnished with a broad reflexed margin. 
Foot small, cylindrical, expanded at the end and grooved. Sexes 
distinct ; generative organs combined with the right mantle lobe. 
Ventricle exposed, not perforated by the rectum. Byssus large, laminar 
passing through a nearly complete foramen in the right mantle lobe, 
and attached by a powerful muscle to the centre of the left valve. 
Adductor moderate ; pallial line continuous. Shell largely indented or 
with a variously formed opening near the summit of the inferior valve, 
for the passage of the adductor muscle, which is attached to a plug that 
adheres to foreign bodies. 
Genus, ANOMIA—Linneus. 
Shell not eared, upper valve with three sub-central muscular scars ; 
the anterior upper lobe of the notch separated from the cardinal edge ; 
plug entirely shelly, and quite free from the edge of the notch. 
A. stowei, Hutton, CALAL, p. 83. Sub-orbicular, thick, solid, 
lower valve smooth ; yellowish-white ; interior dark green ; notch large, 
ovate, anterior lobe widely separated from the cardinal edge ; muscular 
impressions two only, strongly marked; upper large, broadly oval or 
sub-orbicular ; lower much smaller on the posterior lower edge of the 
larger, and confluent with it, sub-orbicular. 
Diameter, 3°5. 
Picton. 
A. alectus, Gray, P.Z.S., 1849, p. 117; Reeve, Conch. Ic., f, 28. 
Irregular, upper valves convex, reddish, internally pearly ; lower valve 
