5 
extreme lateral ones are incomplete in regard to some septa. 
The primaries and secondaries are stout, sub-equal, and larger 
than the rest, which diminish according to order. According to 
Woods the septa are arranged in six systems, but I cannot so 
interpret the calice of any specimen. Тһе columella is longitu- 
dinal and consists superiorly of numerous irregularly shaped 
papilli, which are sometimes, but not uniformly, arranged in 
three parallel rows. In a damaged specimen some papilli are 
broken off and the columella beneath is almost solid, and united 
to the septa. 
The coste correspond to the septa, and are rounded, smooth, 
and glistening, with narrow but deep interspaces. The 
primaries and secondaries reach the extremity of the base, near 
which they аге joined by the tertiaries : the latter again are joined 
by the quaternaries at varying heights on the wall. The more 
central costæ become gradually narrower and the lateral ones 
broader towards the base. The costs of the edges are perhaps 
on the whole slightly broader than those in the centre of the flat 
sides. The wall is thin and there is no epitheca. 
The large specimen figured is 12 mm. high, and its calice is 
9:5 mm. long and 4 mm. broad. 
The fossil analogue of this coral is P. Airensis, mihi, which, 
however, is smaller and less compressed ; its septa also are more 
regularly developed and fewer in number. 
GENUS TREMATOTROCHUS, Tenison Woods. 
Trematotrochus Verconis, spec. nov. Pl. i., figs. da, b. 
This small coral is cuneiform and compressed, with a rounded 
base. Its calice is shallow and elliptical, with the major and 
minor axes in the proportion of 2 to 1. 
The septa are exsert, granular, and in six unequal systems 
with four cycles. In the two central systems the principal 
orders are stout and equal, and increase slightly in thickness 
from the margin to the columella; the quacernaries are shorter, 
much smaller, and taper from the wall inwards. The four lateral 
systems are incomplete, and the septa relatively smaller, except 
the primaries, which are of full size. The calice figured contains 
46 septa, and that of a young individual 40 ; in the latter the 
quaternaries consist of slender points only. 
The columella is essential and longitudinally placed. Super- 
iorly, it is free and nodular, but solid inferiorly, and then fused 
to processes from the principal septa. 
The coste, which are continuations of the septal orders, are 
stout and equal, broadest centrally, and narrow in the lower 
portion of the corallum. On the flat sides nearly all reach the base, 
but laterally the quaternaries join the tertiaries about midway 
