982 Marvels of the Universe 
front part of the lower shell conducting it to the gill- 
chambers. This is a great and important change 
from what is usual in the majority of Crabs, and 
yet it is effected by very slight modifications of the 
prevailing structure. 
In the so-called Squat Lobsters—which are not 
lobsters, but crabs—we have a similar lengthening 
of the trunk; but in this case it is much broader 
behind than in front; and the tail, instead of 
being reduced and folded beneath the body, is 
here kept expanded behind, ready to be suddenly 
flexed in true lobster fashion, to send the animal 
rapidly backwards through the water to some con- 
venient hole in the rocks. The shell of the back is 
crossed by hairy lines, which give it the appear- 
IRO/NDGILAW? CRAB. ance of being composed of overlapping plates, 
Wto oak aad peoedaws ae bol axl din, Gl wae ime tour pais OF less ane covered with 
fringed with long coarse hair that collects mud and dis- half-circular, spine-fringed scales. The fifth pair 
guises the Crab. © 
Photo by] (H. Main. 
of legs are very slender, with a brush-like develop- 
ment at the extremity. In ordinary these weak limbs are not seen, for they are kept folded 
up and tucked under the edge of the shell in the gill-chambers. 
A nearly-related crab, known as the Broad-Claw, is of such exceeding flatness, that he looks as 
though he had been mechanically flattened. This is especially noticeable in respect of the pincer- 
claws, which are remarkably spread out, and their apparent size increased by fringes of long, shaggy 
hair. This gathers particles of mud, and as the crab is fond of clinging to the rocks to which his 
flat under-side closely adheres, he looks like a mere daub of mud. If you take him off—at the cost 
to yourself of a very sharp nip from the pincers—you will find that he is not so dirty as he looks, 
for the under-surface is clean and white, and polished like porcelain. 
A very near relative is known as the Porcelain Crab for a similar reason, though he 
differs from Broad-claw in having a very circular, flat little body, and long, rather eccentrically- 
shaped pincers. His habit is to pack himself away in all sorts of crevices where flatness is 
desirable, but the very broad claw might be in 
the way. 
But the smooth finishing of a crab is carried to 
much greater lengths in the Polished Crab, whose 
portrait appears on page 980. Flat and broad it 
is, and well fringed with hairs, its white surface as 
smooth and shiny as a piece of glass. It lives under 
the sand, and its smooth body, narrowed behind, 
is well calculated to make descent easy. Its 
antenne are fringed like those of the Masked 
Crab; but as they are comparatively short, we 
can see at a glance that it does not bury itself far 
below the surface. 
In the opposite direction we have crabs that 
are as rugged as possible. A little species found 
Photo by] [H. Main. in deep water in our own seas is of this descrip- 
INOS PHO CRABS tion. It lives among corallines, and is got up to 
Here is shown the white and clean polished under-side. : 5 
“ER ecu Ged cidevalaane, elon danere marae resemble them so exactly that when its limbs are 
