316 THE SPINDLE, OR DISTAFF SHELL. 
The Frog-shell seems to have been gifted with its popular name on the same principle 
that caused a well-known dramatic character to detect in a cloud an equal resemblance to a 
whale and a camel. All the members of this genus possess two rows of ridges, technically 
called “varices,” upon the shell, one row being placed on each side. There are about fifty 
species of Kanella, spread over all the warm seas. Like the preceding shells, they prefer the 
shallow to the deep waters, and may be found at almost all depths — from the bare rocks left 
waterless by the receding tide, to a depth of eighteen or twenty fathoms. 
The Bull-frog Shell has a roughly tuberculated surface, with deep hollows and bold 
ridges of thick shelly substance, together with projecting horns on either side. The color of 
this shell is extremely variable. In the handsomest specimens the ground color is creamy 
white, largely mottled with bold tints of deepest brown and purest white. But in many 
instances the entire shell is of a very pale tone, yellow predominating, and the brown 
entirely subservient, and presenting the same contrast to the full-colored shell as the albino to 
the negro. 
The Suits ed Frog-shell derives its name from the sharp and rather long spines or pro- 
jections with which it is furnished. None of these shells are of very great size, their average 
length being about two inches. 
A very pretty shell is termed indifferently the Little Fig, or Little Pear Shell 
{Pyrula ficus), because its general outline is thought sufficiently pear or fig-like to warrant 
the application of the name. Both scientific names refer to this far-fetched resemblance, 
pyrula signifying a little pear, and ficus meaning a fig. 
The foot of the Pyrula is abruptly cut off, or truncated in front, and modified so as to 
form a short horn or partial crescent at each side. 
Nearly forty species of Pear-shell are known to conchologists, and are spread over the 
warmer seas of the world, living in moderately deep water, varying from sixteen to thirty-five 
fathoms of depth. 
This is a thin and delicate shell, the large expanded lip being especially so, and, 
in consequence, is very light when the inmate has been removed. The color is very pale 
yellow, with brown and white arranged in wavy mottlings. Its average length is about four 
inches. 
The delicate thinness of the shell is not, however, a character common to the entire 
genus, for another species, the Bat-like Pear-shell ( Pyrula carnaria ), is quite as remark- 
able in the opposite direction, its shell being peculiarly large and ponderously constructed. 
This shell is found in the Indian Ocean, and its general color is dark bay. In all these 
shells, however, the long canal which projects from the front of the shell is always open, not 
being filled up with solid matter as the animal increases in age ; and the columella, or pillar 
of shelly substance, which runs up the centre of the whorls, like the solid centre of a screw, is 
always smooth. 
A large and boldly mottled shell, popularly known by the really appropriate name of 
Tulip Whelk, bears in its rich and variegated coloring some analogy to that of the flower 
from which it derives its name ; while the general shape is sufficiently like that of the whelk 
to warrant its use, even though the two shells belong to different families. The generic name 
of this shell is derived from a Latin word signifying a band, and is given to it on account ojL 
the boldly banded stripes in which the colors are disposed. As in the last-mentioned genus, 
the canal, though not so elongated, is always kept open. 
Comparatively few living species of Tulip-shells are known to conchologists, sixteen or 
seventeen being their utmost limit. These shells inhabit the warmer seas, and some of them 
attain a great size, such as the Great Tulip-shell, which sometimes reaches a length of 
nearly two feet. 
Before mentioning our last example of the Muricidse, we have to pay attention to the 
Spixdle, or Distaff Shell ( Fusus coius ), so called in allusion to its form. Its scientific 
