46 
SURVIVAL OK LAND AKB SEA 
are two types that are more or less dangerous. These are the 
so-called needle-urchins and the soft-bodied urchins. 
The needle-urchins are from 2 or 3 to 6 inches in diameter, 
black or more or less reddish, with very long and slender needle- 
pointed spines which may reach 10 or even 15 inches in length. 
These spines are provided with whorls of minute barbs and are 
very brittle, breaking off after penetrating the liesh. One form 
of needle-urchin found throughout the Indo-Pacific region but 
not in the Atlantic has, in addition to the very long spines, 
numerous shorter, much more slender, and smooth spines which 
are connected with poison glands. These shorter spines are 
definitely dangerous even to touch, as they discharge an active 
and painful poison. 
The soft-bodied urchins occur in shallow water throughout 
the Indo-Pacific region, but not in the Atlantic or along the 
west coast of tropical America. They reach a diameter of nearly 
7 inches, and are much flattened. The usual size is between 3 
and 6 inches. They vary in color from dark purplish or greenish 
hues to white, and often are more or less extensively marked 
with red. Some are almost wholly red. Usually they show an 
iridescent blue tinge. The shell is flexible, feeling somewhat 
like parchment, and is not rigid like that in most sea urchins. 
The spines are short and fine, rather widely scattered, and are 
exceedingly sharp. Some of them, more slender than the others, 
are provided with glands that secrete a very powerful poison 
that produces effects similar to those caused by the poison from 
the bites of sea-snakes or cobras. To be certain whether a sea 
urchin is soft-bodied or not poke it with a stick or some other 
object before you touch it with your hand. 
