MADREPOEAEIA OF THE DEEP SEA. 331 



LOPHOHELIA FROLIFEEA, Pallas, Sp. 



The corallum is tall, and either dendroid or boat-shaped ; and the corallites often 

 unite laterally. 



The corallites are long, turbinate, subturbinate, cylindrical, claviform, and cyathiform, 

 or short. They are often deformed. 



The wall is finely granular. 



The costce may exist as crests here and there, as very fine curved lines, or they may 

 be absent. 



The wall is thick, especially inferiorly. 



The calicular margin may be circular, elliptical, or deformed in outline ; it may be 

 open, inverted, everted, or not. 



The calicular fossa may be very deep, or may be crossed by tabulae at different depths. 



The septa are never in three, four, or five perfect cycles in six systems. The number 

 of the larger septa varies, as does the amount of the exsertness, projection outwards, 

 and breadth. 



The septal laminae are unequal, larger and thicker at the margin than elsewhere, and 

 they approach each other at the bottom of the fossa. 



The septal ends are usually not in contact; but occasionally some trabecula; join them 

 low down. 



The tabulae are thick and variable in their position. 



The dissepiments are small, and rarely extend beyond the interseptal loculi. 



The height of the corallum and the size of the corallites vary greatly. 



The variability of the group of forms included in this species is extreme. On one 

 stem corallites which answer to Lophohelia prolifera, Pallas, sp., L. anthophyllites, Ellis 

 & Solander, sp., L. mbcostata, Ed. & H., L. affinis, Pourtales, L. defrancei, Defrance ', 

 and L. stoppiniana, Seg.', can be observed ; and other stems, or rather independent 

 corals, consist of corallites possessing the special attributes of one of the species only. 



The coalescence of the corallites varies in amount, as does the thickness and weight 

 of the corallum. 



In some large corallites, with calices measuring \ inch in breadth, there are four 

 cycles and some septa of the fifth; but usually in calices of less size the fourth cycle is 

 incomplete. 



Two specimens were dredged up in the Mediterranean (No. 58, depth 266 fathoms), 

 between Sicily and the African coast ; and thus the coral must be received as one of the 

 fauna of the Mediterranean, although previously doubt had been cast upon it. 



Its usual habitat is in the North Sea, the North Atlantic, and off the French and 

 Spanish coasts ; and it frequents rocky ground. 



' Fossil species. 



