450 CLASS ECHINODERMATA. 
There are some also whose contour is not angular. (Ech. 
oviformis, Seb.) 
And even where it is almost orbicular. (LAGANUM, Klein. 
Echinus orbiculatus.) 
FIBULARIA, Lam. ECHINOCYAMUS, Leske., 
Have, with the rose of the clypeaster, the body almost globu- 
lar, and the mouth and anus approximated in the middle of 
the under part. They are usually very small. (Hcehinus 
nucleus, Kl., &c.) 
On the contrary, SPATANGUS, K/., have, with the lateral 
mouth of the ananchites, some incomplete bands of pores, 
forming a rose on the back. There are usually but four ; that 
which is directed from the side of the mouth is obliterated. 
Some, BRESSOIDES, Kl., have the testa oval, without 
furrows. (Ech. teres, Seb.) 
Others have a large sulcus more or less marked, in the 
direction of the obliterated band. (Ech. spatangus, Seb., &c.) 
When, besides this, they preserve the oval form, they are 
Brissus, Kl., but sometimes this sulcus grows deep, and 
the testa widening at the same time on this side, assumes 
the figure of a heart. (Ech. purpureus, Miill, &c.) 
We have some in our seas of the last two forms. Branched 
tentacula, like those of the holothurie, have been observed 
round the mouth. 
HoLoruurRia,, Lin., 
Have the body oblong, coriaceous, and open at the two ends. 
At the anterior extremity is the mouth, surrounded by very 
complicated branched tentacula, which can be completely 
retracted. At the opposite extremity opens a cloaca, where 
terminate the rectum and the organ of respiration, in the 
form of a hollow tree, very much ramified, which is filled with 
