ORDER PEDICELLATA. 44.7 
Some round and depressed echini lose something of their 
regularity by a wide sulcus, with which they are furrowed on 
one side. (Ech. sinuatus, KI.) 
There are also some of these echini with mouth and anus 
opposite, which, instead of having the spheroidal form on a 
circular plane, are transversely oval, that is to say, one of 
their horizontal diameters is larger than the others. (Ech. 
lucunter, K1.) 
They also differ among themselves by the equality or in- 
equality of the prickles, and by the relative proportions of the 
tubercles. 
One species should be distinguished,—Echinus atratus, 
L. Encyc. 140. 1—4, in which the prickles, widened, trun- 
cated, and angular at their extremity, touch each other there, 
like pavement. Those of the margin are long and flatted. 
We call irregular, all the echini in which the anus is not 
opposite to the mouth. It appears that they are furnished only 
with short and slender prickles, almost like hairs. Among 
them some still have the mouth at the middle of the base. 
They may be subdivided, according to the extent of the bands 
of holes for the feet. Sometimes these go, as in the preceding, 
from the mouth to a point directly opposite, or they unite 
after having embraced the entire testa. In the former, the 
ECHINONE, Phelsum and Leske, 
Have the round or oval form of certain regular echini, the 
mouth at the middle of the base, and the anus between the 
mouth and the margin, or near the margin, but underneath ; 
oval species, Echinus cyclostomus, Miill., &c. ; round species, 
Ech. depressus, Walch, &c. 
NUCLEOLITES, Lin., 
Have, with these characters, the anus near the margin, but 
above. 
