33 
the narrower and higher extremity. This species is only known as a 
fossil ; in which state the granular surface is generally removed. 
Spatangites subglobosus, Tab. liv. Fig. 2, 3. This shell is cordated, 
and, on each side, convex and subglobose ; with ten striated and bi- 
poi ous ambulacra. Leske adds to these the following characters : — 
Four pores, in the angles of a trapezium on the vertex ; also, in the 
apex, where the two pores unite, a little pit is impressed. The two 
neighbouring ambulacra form triangles, the bases of which are in the 
periphery, and their apices in the vertex. Two rows of pores in the 
dorsal lacuna reach to the mouth ; and, from the vertex to the anus, 
a prominent lidge proceeds. Each area is divided by a serrated longi- 
tudinal suture, and is divided into assul® by transverse lines, slightly 
arched : the assulee of the larger areas are heptagonal, and those of 
the less area; are alternately heptagonal and pentagonal. The cir- 
cumference of the middle of the base is granulated ; but the superior 
surface is generally so worn, as to show only the traces of the gra- 
nulas .- two fascia, free from granuke, extend from the angles of the 
mouth towards the anus. The mouth, which is subreniform, is near 
to tlie grooved margin, and is surrounded by tubercles, disposed in a 
stellular form. . The anus is near to the superior margin of the nar- 
lower and undivided extremity. 
This description is given more fully, since the figures given by Leske 
do not accord with that of Lister, to which he refers. The figure given 
> alch, Tab. e. iv. Fig. 3, 4, agrees exactly with that of Leske. 
Spatangites ananchytis, Tab. lih. Fig. 1, 2, Lesk. differs from the 
preceding, chiefly m its upper part being more conical, its base more 
flat, and its periphery more oblong. The figure given by Leske is 
from a silicious nucleus ; and the only specimen of this fossil, which 
I possess, is a spathose nucleus. 
Ananchytis, sen Synochitis, of Mercatus, p. 316, and App. 89, ap- 
pears to approach much nearer to the form of Spatangites globosus , 
than to that of this fossil. 
vol. in. 
F 
