20 
ORCHESTIIDiE. 
third from the apex. The structure of the hair towards 
the point is obscurely spiral. Those 
upon the tail are often considerably 
worn down by the friction induced 
by leaping. The central tail-piece is 
represented in this species by two 
small calcareous nodules. * The 
surface of the body is highly polished. An examina- 
tion of the structure of the integument by the aid of the 
microscope shows traces of the original cell-character of 
the tissue and the granular arrangement of the salts within 
the cells. There are, moreover, certain larger markings 
that assume somewhat the form of the letter t. But we 
are not able to recognize them as associated with any 
peculiar function. 
The female exhibits the character of the species 
less strikingly than the male, being considerably smaller, 
and having the antennae shorter. So great indeed 
is the difference, that Leach, in the “ Edinburgh Ency- 
clopaedia,” inserted it as a distinct species, under the 
name of Talitrus littoralis , an opinion which he afterwards 
corrected in the “ Linnaean Transactions,” vol. xi. 
The Sand-hoppers dwell near the margin of the sea, 
where the highest spring-tides rise. They are never 
found in the water, but dwell beneath the decaying sea- 
weed, or other stray substances which preclude the eva- 
poration of moisture from the scorched sandy beach. Mr. 
Gosse tells us that he has found them at the depth of 
several inches in half-rotten beds of algae, where the fer- 
* Our figures in page 16 were taken from very large males, captured at 
Weymouth, by Professor Bell. In these individuals the central tail-piece is 
heart-shaped and spined (fig. z), and the upper antennee extend to the tip of 
the penultimate joint of the peduncle of the lower, of which latter the rela- 
tive proportions of the joints were carefully measured for delineation. — (W.) 
