397 



On two Neav Genera q/" Alcyonoid Corals^ taken In the 

 recent Expedition of the Yacht Norna off the Coast 

 of Spain and Portugal. By W. Saville Kent, 

 F.G.S., F.R.M.S. of the Geological Dejiartment, British 

 Museum. 



(Plate XXI.) 



Fam. ALCYONIU^, M.-Edw. 

 Sub-Fam. Cornularin^j ib. 

 Gen. nov. Gymnosarca. 



Coralhmi of firm consistence^ its surface smooth ; attached 

 by its base and partially incrusting ; throwing off free cylin- 

 drical stolons, which give rise to solitary elevated polyp-cells. 

 Stolons occasionally branching, coalescing with each other, 

 or forming a bond of attachment with any foreign object 

 with which it comes in contact. Polyp-cells cylindrical ; 

 animals semi-retractile, forming an ovate head when most 

 retracted. 



G. bathybius, PI. XXI, figs. 1—4. 



Diameter of the cylindrical stolons one eighth of an inch ; 

 height of polyp-cells one tenth of an inch, of the partially re- 

 tracted polypes one eighth of an inch. Colour of the general 

 coenenchyma pale yellow, of the polypes and polyp-cells 

 flesh-pink. Spicula of the coenenchyma colourless, more or 

 less irregularly fusiform and cchinate, occasionally slightly 

 branching ,• those of the tentacular region of the same type 

 mixed with a few more slender arcuate forms. 



Hab. Off the coast of Cezimbra, Portugal, at a depth of 

 500 fathoms. Parasitically attached to Lophohelia protifera. 



The firm consistence of the coenenchyma of this coral is 

 due to the innumerable colourless, irregular, echinate spi- 

 cula, which occur in profusion throughout its substance, but 

 which lying beneath its surface are not visible exteriorly. 

 The parasites of spicula of the same type mixed wdth slender 

 arcuate forms, met with in the tentacular region, and where, 

 owing to the tenuity of the investing membrane, they are 

 eminently conspicuous, sufficiently accounts for the inability 

 of the polypes to withdraw for protection within the cavities 

 of the polyp-cells ; a fact also serving to demonstrate that 

 the generic or family characteristics based upon the pos- 

 session or non-possession by the animals of this capability are 

 supported by evidence of histological structure, in addition to 

 that afforded by mere external appearances. 



VOL. X. — new ser. d d 



