39 
In a fossil from Hertfordshire, in which an echinite, probably of the 
variolated kind, is involved in a mass of pyritous clay, innumerable 
subulated and capitated aciculas are seen piercing through and laying 
in the surface of the mass. 
The capillary aciculae are so small as to give but little chance of de- 
tecting them, mineralized, in an attached state ; and I know but of one in- 
stance in which they have been found petrified and adherent. This has 
lately occurred in a mass of silicious cordated echinites from Devon- 
shire, imbedded in a matrix of chert. In this specimen, the capillary 
aciculai spines are accumulated on the echinites in prodigious numbers. 
The spines comprised in the class of Sudes are very numerous ; but, 
or the reasons already related, the spines of this class, in the state of 
petrifaction, are very rarely found in attachment with their shell. The 
first genus of this class, Suites villarum, Stakes, is divided into three 
species : 1. Icevis ; 2. nodosa; 3. granulata and striata; 4. torosa, 8fc. 
Of the first of these species, I have not, to my recollection, seen a spe- 
cimen ; the glass making some configurations appear on the surface of 
all which I have examined of this genus : nor have I seen any of the 
second species, simply knobbed, the lens generally showing strife also. 
the third species, granulated, there exist many varieties ; among 
which, indeed, are several apparently deserving of being considered 
aS -fE S ^ I1Ct - SpeC,eS ' Plate IV ' Fig - 3 5 re P re sents a cylindrical species, 
T? 1 enticulated rings, which is adherent to its shell, by which we 
. 1?C °\ C1 ^ belongs to one of the Cidares papillatce. This spine 
is capitated , and, if it were not in a slight degree tumid at its com- 
mencement, might be considered as completely cylindrical It is 
surrounded by eight rows of denticulated granule, the surface between 
which is minutely striated. In one specimen which I possess, these 
spines, very little superior, as to thickness, to those which are here 
represented, are full five inches and a half in length. 
Of one variety of the torose, or knobbed sudes, a fragment is repre- 
sented Plate IY. Fig. 5 and now take a view of Vol. I. Plate YI. 
