20 BRITISH FOSSIL CORALS 
Locality. Upper Greensand of Cambridgeshire. In the Collection of James 
Carter, Esq. 
4. Sminorrocuus ANGuLATuS, Duncan. PI. VIL, figs. 7, 8. 
The corallum is conical, hexagonal, and slightly curved at its very fine inferior ex- 
tremity. It is broad superiorly, has six prominent angles, and is slightly compressed. 
The septa are fine, unequal, and each plane between the angles has a system of four 
cycles. 
The columellary space is large. 
Height, sths tol inch. Breadth, } inch. 
Locality. Upper Greensand, Cambridge. In the Collection of James Carter, Esq. 
ONCHOTROCHUS. 
Genus 
Oncnorrocuus Cartert, Duncan. PI. VIII, figs. 1—14. 
In the young corallum there is a flat and rounded expansion at the base, by which it 
was attached to foreign substances, but this is lost as growth proceeds. 
The corallum is either straight or slightly curved, is tall, very slender, cylindro- 
conical, clavate, and enlarged here and there. 
The worn specimens are more or less angular in transverse outline. 
The costae are angular projections, which extend from base to calice; they are sub- 
equal, wide apart, and are connected and covered with a fine, striate, pellicular epitheca, 
which readily disappears. 
The growth-markings are very common. 
The calice is circular and shallow. 
‘The septa are stout at the walls and wedge-shaped ; they are rounded superiorly, and 
do not extend far inwards. There are twelve septa, and they are subequal. ‘The septa 
in sections often appear to be equal, and their inner ends are joined, and the axial space 
is filled up by a deposit of coral structure; but the reverse is the case occasionally, and 
the irregularity of the septa may often be well seen. ‘The septa are continuous with the 
coste. 
Height, 1rd—?rds—1 inch. Diameter of costa, jth—Jth inch. 
Locality. Cambridge Greensand. In the Collections of James Carter and Rev. 'T. 
Wiltshire, F.G.S. 
