REPORT ON CORALS — DEEP-SEA MADREPORARIA. 167 



four or five stout ragged outgrowths from the bases of the septa only, which do not fuse 

 but leave the interior of the calicle open to the view to its very apex ; in others similar 

 but smaller processes are present more abundantly, and join one another to form an 

 elongate mass connecting the bases of the septal margins. 



A complete series of young specimens of this coral was obtained. The youngest 

 calicles occur attached to the adults. They are closely similar in form to those of 

 Flabellum aldbastrum (PI. VII. fig. 2, a, b). They are at first oval, in transverse 

 section, with slight indentations opposite the origins of the septa. They have six 

 well-marked, nearly or quite symmetrically disposed primary septa, and six secondary. 

 The primary septa do not reach the centre of the calicle until the wall of the 

 calicle has risen to some little height ; the secondary septa are much shorter than 

 the primary, and in one specimen the secondary septa are absent in the pair of 

 chambers at one end of the long axis of the calicle. There is, however, no proof of an 

 original condition with only six septa. As the young calicle rises higher it becomes 

 hexagonal in section, and widens out rapidly. It shows a series of accretion lines, which 

 are sometimes so marked as to give the appearance of a new coral budding out of the 

 interior of an old one. As will be seen from the series figured on Plate XV. the septa 

 appear to develop with great regularity in all the systems equally, and the full number 

 of septa is very early attained. 



The coral appears nearly allied to Flabellum thouarsi (Milne-Edwards and Hainie), 1 

 which occurs at the Falkland Islands ; but in that species there are five systems, 

 whereas none of the largest specimens of Flabellum patagonichum show any trace of a 

 fifth system. 



Extreme height of the largest specimen, 23 mm. Long diameter of the calicle, 

 28 mm. Short diameter, 21 mm. Long diameter of the newly-formed young calicle, 

 2'5 mm. Short diameter, 2 mm. 



Station 305, off Penguin Island, Patagonia. 120 fathoms. Numerous living 

 specimens. 



Flabellum apertum, Moseley (Proc. Eoy. Soc, 1826, p. 556). '(PI. VI. fig. 7, a-c.) 

 The corallum is much compressed at the base, where it forms a short pedicle, which is 

 attached in one specimen (that figured in the woodcut) to a minute rolled particle of 

 basalt. Above the pedicle the walls of the corallum curve outwards so as to form a 

 widely-open, almost cup-shaped, calicle. The summits of the calicle at the termination of 

 the long axis are a little lower than those at the termination of the short axis. The wall 

 of the calicle presents twelve prominent costal ridges separated by intervening rounded 

 excavations. The primary ridges are more marked than the secondary, and the lateral 

 costas slightly more prominent than the others, and continued almost to the apex of the 



1 Millie-Edwards and Hainie, Hist. Nat des Corall., t. ii. p. 89. 



