448 CLASS ECHINODERMATA. 
The known species are all fossil. (Spatangus depressus, 
Leske.) 
Others, 
GALERITES, Lam. CONULUS, K1., 
Have a flat base, on which their body is raised like a cone, or 
a semi-ellipsoid figure. The mouth is at the middle of the 
base, and the anus near its margin. 
They are very common in rocky strata, but no living species 
are known. 
The most extended is Ech. vulgaris, L. Encyc. 153. 6—7. 
Klem. Ed. Fr. VII. D. G. 
Some have not their bands of holes distributed in the 
quinary number. Ech. quadrifasciatus, Walch, &c. 
SCUTELLA, Lam., 
Have the anus between the mouth and the margin, the testa 
exceedingly depressed, flat underneath, and of a form ap- 
proaching to orbicular. 
Some have it entire, and without any other holes than the 
series of little pores which are seen in all the echini. 
Others have the testa equally, without large holes, but 
divided by two emarginations. (Hchinus auritus, Seb., &c.) 
Others have it entire, and pierced from interval to interval, 
by some large holes which do not penetrate into its cavity. 
(Echinus hexaporus, Seb., &c.) 
Others have it at once emarginated, and pierced with three 
large holes. (Echinus tetraporus, Seb.) 
There are some, in fine, RoTULH, KJ., in which a part of 
the posterior margin is festooned, like a dentated wheel, and 
these are divided according as they have large holes. (Kch. 
decadactylus, Encyc.;) or according as they want them, 
(Echinus orbiculus, Encyc.) 
CASSIDULUS, Lam., 
Are oval, and have the anus above the margin, like the 
