188 CATALOGUE OF THE MOLLUSCA 
form among the Conchefera. All the bivalves hitherto known 
have the siphons, when there are any, at the posterior end of the 
shell: the peculiarity of this genus is—that it has a large si- 
phonal tube in front, as well as a short one behind. The ani- 
mal of Kellia suborbicularis is white and semi-transparent ; the 
mantle has three openings ;—the first is in front, and is produced 
into the siphonal tube above mentioned, which is very broad, and 
can be extended to a length equalling the diameter of the shell. 
This tube is not divided inside, and the margin of its aperture is 
plain. The second opening, which is at the base of the shell, is 
the largest of the three, and gives egress to a longish strap- 
shaped foot. The third opening is posterior, and forms a very 
short siphon, seldom protruded beyond the shell. The margins 
of these apertures are smooth, but there is a very delicate fringe 
of small and distant filaments, close within the margin of the 
shell, which can only be seen when the animal is fully extended. 
With a good magnifier, a current of water may be observed to 
pass in at the anterior siphon, and to be expelled at intervals by the 
posterior one. The animal moves about freely by means of its 
strap-shaped foot, which is frequently protruded in all direc- 
tions. Its progress is usually forwards, but, sometimes, it crawls 
backwards or sidewise, especially when it is ascending a perpen- 
dicular surface, which it frequently does for the purpose of sus- 
pending itself by its byssus. The byssal aperture is about half- 
way up the foot on the posterior surface, from 
which the animal produces a very delicate 
thread, and suspends itself freely by a single, 
almost inconspicuous, fibre, strengthened by a 
double attachment at the top. The accompa- 
nying figures represent the animal (a little 
magnified) in a state of activity, and also sus- 
pended by its byssus in a state of rest. 
2. K. rusra, JZont. 
Cardium rubrum, Mont. Test. Brit. 83, t. 27, f. 4. 
Among small sea-weeds near low-water mark, Whitley.—J_ 
H. F. At the roots of Lichina pygmea, on the rocks below 
amborough Castle—Mr. W. Thompson, of Belfast. 
