92 
therefore venture to conjecture that they do not cast their 
spines nor case, as lobsters do. 
These things are extremely difficult to make out } and if 
we should make any mistake, it may be so far successful as 
to be the cause of finding out the truth. 
There is the same species recent at the British Museum j 
and one of them has the spines over the foraminous aper- 
tures turned back : perhaps, they are commonly so when 
alive. We do not know from whence they come. 
On looking over Klein, we found a figure which appeared 
to be the same as ours, and which Gmelin quotes as 
var. a. of his Echinus cidaris. We also find a specimen in 
Mr. Woodd’s most respectable collection, which seems to 
have been taken in a living state. On examining all the 
specimens with a great deal of attention, we find the fo- 
ramina constantlv different from the New Holland one; we 
therefore suspect that it is another species, and ought to 
have a new name. The double foramina are situated in 
simpler-formed bones, which are thickest at one of the 
ridges ; when the animal’s mouth is downwards, they seem 
to lap over each other like tiles. The New Holland one has 
strong indentations between the double foramina, and the 
bone forms a kind of beak-like process, curving into the 
holes — see figs. 1. 2. As these animals are often admired 
when destitute of spines, it may be necessary to observe 
another difference in the bones. The five divisions destitute 
of foramina have, as we before observed, six rows of 
spines ; consequently they have six rows of tubercles, 
suited for the sockets of the spines, somewhat distant. 
Those from New Holland are more equal in size, move 
crowded and numerous : see figs. 3. t. 
We do not think that the figure of a petrified specimen 
referred to by Gmelin, in Klein, is the same species. We 
have specimens sufficiently preserved to see the difference, 
which will be figured in lal. 152 of British Mineralogy . 
