APPENDIX, 521 
minute points of flaky matter of similar hue. The tentacula 
are flat and strong, and rather clavate at the tips; the eyes 
are always carried considerably within the margin of the shell. 
The foot is narrow, and when fully extended, as long as the 
shell, with a rather pointed termination. ‘The caudal cirrhus 
of the opercuwlar lobe is very long and distinct, flattish at its 
insertion, and tapering to a fine pomt. This animal is nearly 
a true Rissoidean. Axis 7,, diameter 1, uncie, in ordinary 
specimens. . 
Asstm1nta.—(P. 380.) 
Assiminia is not placed in the same order as in the Classi- 
fication, it being removed, provisionally, between Rissoa and 
Truncatella, as we think, when the animal is better known, it 
will belong to the latter genus. 
We have in vain called on naturalists to furnish us with 
some of these animals; they abound in the tidal ditches of 
the Greenwich and other eastern marshes; if they were sent 
by post on the day of capture, im an ounce bottle filled with 
the water or moist mud they inhabit, enclosed in a tin 
cylinder or small wooden box, they would arrive sufficiently 
lively for examination. 
CHEMNITZIA PALLIDA.—(P. 415.) 
The rostrum, or head, is short, broad, rounded or sub- 
circular at the end, shghtly grooved to its base, and speckled 
with yellow pomts. The tentacula are not short, but long, 
subtriangular, not pointed, and have very distinct, small, 
flake-white terminal inflations; they are bevelled, rather 
setose, narrow, not much folded or auriform. The animal, 
and those of all its numerous varieties, viz. C. dubia, C. alba, 
C. nitida, C. albella, C. rissoides, C. eulimoides, and C. gla- 
brata, are more or less variously suffused with very minute 
yellow points, as well as speckled with irregularly deposited 
dots or larger pomts of sulphur-yellow, of various intensity of 
hue; this characteristic colouring will always detect the 
C. pallida or any of its varieties, as no other Chemnitzia 
that can be confounded with it is thus painted. 
