460 Mr. W. S. Kent on Madreporaria. 
he distinguishes from D. crista gall simply on account of its 
prominent and persistent costze. 
Fam. Oculinidz. 
Lophohelia prolifera, M.-Edw. 
under, we may presume, modified external conditions. Dr. 
. M. Duncan has already pointed out (‘ Porcupine’-Expedition 
Madreporaria, Proc. Ro 1870) that the form hitherto 
sented among the examples taken in our recent dredging- 
cruise; and their study has suggested the following as the in- 
terpretation of the causes at work which bring about this par- 
ticular modification of form. One of the masses now before 
me exhibits at its base the short wide-mouthed calices with 
the characteristic exsert primary septa of Lophohelia prolifera, 
while above, and springing from them, are the attenuate and 
frequently almost cylindrical forms with little-exsert septa, 
which constitute the leading features of L. anthophyllites. On 
arriving on board our yacht the whole basal portion of this 
specimen was invested and all the interstices filled up with 
mud; and this, in connexion with the attenuate or, so to say, 
drawn-up character of the superiorly situated calices, would 
seem to indicate that at a certain period of its living history a 
greater deposit of sedimentary matter had taken place in the 
ocean bed; the coral-colony was consequently threatened with 
speedy destruction, and in the struggle for existence it had 
thrown off these longer forms of calices, which would serve to 
raise it up beyond the action of the untoward conditions then 
existing. This interpretation is further strengthened by the 
direction of the calices in the two extreme portions of the 
mass: in the lower part they all follow an irregular horizontal 
ied . 
disposition, while in the upper one they are all directed per- 
