26 BRITISH FOSSIL CORALS. 
towards the basis, rather prominent; and subcristate near the calice, covered with 
granulations, which become much larger towards the calice, and varying in number (17 in 
one specimen, 18 in another, and 22 ina third); about two thirds of them begin at the basis 
of the corallum, and the others about half way up towards the calice, but all are of the same 
breadth ; the position of these younger costz does not appear to be constant, for some are 
separated by three longer ones, and others by two, or only one; in general, however, two 
long ones are placed between two short ones, so that the latter are only about half as nume- 
rous as the former. The ca/ice is nearly circular, or slightly elliptical, and the fossula appears 
to be deep ; we are also inclined to think that there is no columella, and that the septa are 
free all along their inner edge, but the calice bemg clogged up with carboniferous matter in 
all the specimens that we have seen, we haye not been able to determine these points with 
any degree of certainty. The mode of arrangement of the septa is quite abnormal; three 
vertical plates advance from each of the costs towards the centre of the visceral chamber ; 
they are all extremely thin, broad, somewhat flexuous, free from all adherence among 
themselves, and rendered echinulate laterally by a few prominent granulations ; the plate 
placed in the middle of each of these groups is rather thicker than the others, and the 
space existing between it and the latter is rather larger than that comprised between the 
lateral laminze of two neighbourmg groups. Height of the corallum, about four lines; 
long axis of the calice, three lines and a half; short axis, two lies and a half; breadth of 
the costs, more than half a line. 
The three specimens of this species, from which we have drawn up the preceding 
description, belong to Mr. Bowerbank’s paleontological collection, and were found at 
Highgate; Mr. Prestwich has met with it also at Clarendon Hill.’ 
Dasmia Sowerby: is the only known species of this genus which by its general 
characters appears to be closely allied to the family of Turbinolide, but differs from it, 
and even from all the other Zoantharia, by the abnormal structure of the septal apparatus : 
when our attention was first called to this point, we endeavoured to explain the mode of 
radiation of the calice by supposing that each of the laminz corresponding to the middle 
of the costa belonged to one cyclum, and that the two lateral lamine of two neighbouring 
groups, corresponding to the two sides of each intercostal furrow, represented the two 
halves of septa belonging to another cyclum ;” the slight difference in the thickness of the 
middle and the lateral lamin, as well as the facility with which the two constituent plates 
of the septa separate from each other in some Corals, had induced us to admit that this 
structure was only an exaggerated form of that which is frequently met with im certain 
‘Turbinolida, in many species of Flabellum, for example, where the line of junction of the 
two lamine that constitute each septum is indicated externally by a single costal ridge. 
But a more attentive study of this singular fossil has made us change our opinion, and 
! Journ. of the Geol. Soc. of London, vol. iii, p- 368. 
2 Monogr. des Turbinolides, loc. cit. 
