162 THE VOYAGE OF H.M.S. CHALLENGER. 



Station 308, off Tom Bay. 175 fathoms. 

 Station 311. 245 fathoms. 



Desmophyllum eburneum, n. sp. (PL VI. figs. 1, la, lb). 



Only imperfect specimens of this species were obtained. The corallum is of a pure 

 white. It is elongate conical in form, slightly compressed, with a long cylindrical pedicle 

 which expands slightly at the broad base of attachment. The outer surface of the 

 corallum is remarkably smooth and polished, and glistens like polished ivory. The 

 primary, and in some specimens also the secondary costse appear on the surface, where the 

 corallum begins to expand, as slightly prominent ridges, here and there roughened by 

 slight indentations. The development of the costse varies much in different specimens, 

 as also the amount of exsertion of the septa. The primary septa are prominently exsert 

 and sometimes unequally so, and some are bent over outwards beyond the margin of the 

 calicle. In some specimens the secondary costse are as far exsert as the primary ; the 

 tertiaries are only slightly «xsert. There are six systems of septa and four complete 

 cycles. The septa are straight and thin, and are covered on their faces with sparsely 

 scattered, small-pointed granules. Only the primary and secondary septa extend to meet 

 one another laterally around the centre of the calicle^ where their perpendicular margins 

 surround a deep but narrow fossa. 



Judging from the broken specimens, the height of the full-grown calicles is probably 

 about 35 mm. Extreme breadth of a perfect calicle, 21 mm. 



Station 306. Off Middle Island, Patagonia. 345 fathoms. 



Desmophyllum cailleti, Duch. and Mich. 



Desmophyllum cailleti, Duch. and Mich., Supp. M(5m. Coral, 1874. 



A single dead and partly decayed specimen obtained off the Virgin Islands appears 

 referable to this species ; if so, it is large, measuring 30 mm. in height, and 20 in 

 diameter of the calicle. 



Station 24. Off Culebra Island, Danish West Indies. 390 fathoms, 



Flabellum, Lesson. 



Notes on the Structure of the Soft Parts of Species of the Genus Flabellum. 



When a specimen of a Flabellum hardened in absolute alchohol is decalcified, no trace 

 of any external layer of soft tissue covering the outer surface of the wall remains. The 

 living tissues in Flabellum are confined to the interior of the calicle and the immediate 

 outer edge of its margin. The decalcified mass of soft tissue which occupied the interior 

 of the calicle, consists of twelve wedge-shaped lobes connected together at their narrowest 

 ends by means of the central stomach of the animal. The interior of each of the lobes 



