35 
Spatcmgites ovalis, Tab. xli. Fig. 5, Lesk. copied from Walch, 
Fab. e. hi. Fig. 6, is particularly interesting, in consequence of two 
of the ambulacra, proceeding from two points, at nearly half an inch 
distance from each other. The bands formed by three pair arise at 
the vertex of the shell, the middle one passing straight, and the 
lateral ones obliquely, to the region of the mouth ; whilst the two 
posterior pair proceed from a point of the shell just above the anus, 
and pass round the margin on each side of the anus. The specimen 
figured Plate III. Fig. 3, differs from that of Leske and Walch in 
being larger, and not having its parts so distinctly visible, as to be 
able to determine the form of the assuhe ; which, in the otherwise 
"very correct description of this fossil by M. d’Annone, are said to be 
quadrilateral, whilst in the figure they are depicted pentagonal. 
Three species appear to exist in a fossil state, in which the ambulacra 
do not arise from the same point in the vertex of the shell. 
The specimen figured Plate III. Fig. 8, is evidently of the family 
brissoides, and might be named Spatcmgites brissoides ovalis. The 
form is oval ; the base concave, and rounded at its margin : in the 
centre, where the mouth, which is oval, is placed, the ten biporous 
ambulacra terminate separately : the back is convex ; near the centre 
of which are four foramina, and the superior lanceolated terminations 
of each pair of ambulacra : the anus, large and pyriform, is placed on 
the back, just above the margin. 
Ihe following species deserve, perhaps, as is observed by Leske, 
to be considered as forming a distinct genus, which might be placed 
between echinanthus and spatangus. 
Echinites pyriformis, Tab. li. Fig. 5, 6, and Tab. xliv. Fig. 7, 
Lesk. The shell is ovate, gibbous, and rather acute at one end ; the 
base flat. On the back originate five porous, sub-petalous, ambulacral 
bands, which reach to the periphery : a carinated line divides the back 
of the shell, as it were, in two parts. In the middle of the base is 
the round sub -pentagonal mouth, furnished with five prominent lips. 
