IlEPOET ON THE ALCYONARIA. 129 



spindle narrows abruptly before its apex and then gives origin to a sharply marked ofi' 

 process, which is sometimes bent at an angle. Often also the point of the spicule is 

 bent, hook-like ; further, one end may be rounded ofi" or both ends may be blunted. 

 The spindles are thickly covered with small warts, which stand out straight and whose 

 surfaces are again covered with minute spines. Usually these are less thickly placed 

 than in the spicules of the preceding species. Size, 1'6 by 0'12 ; 1"0 by 0"25 ; 1"6 by 

 0-14; 1-G by 0-12; 1 by 0-183; 1 by 0-125; 2 by O'lS mm. Spicules having an 

 average length of 1 mm. predominate, hence they may be easily seen in the ccenenchyma 

 even with the unassisted eye. 



In the calyces the spicules are spindle-shaped and rounded off at the basal end, and 

 stand vertically or obliquely upon the ccenenchyma. They usually project from the 

 base to the margin of the calyx, and form eight not very distinctly separated groups. 

 They measm-e 0-8 to 1 by 0-125 mm. The tentacular operculum is always composed of 

 eight series of from two to three converging spindles, lying in the base of each tentacle. 

 Beneath these there is a well-developed colleret of bent spindles. All these are covered 

 with short, sharp, not very thickly set spines. The spicules of the colleret measure 

 0-G7 by 0-067 ; 0-75 by 0-075 mm.; those of the tentacular operculum, 0-36 by 0-05 ; 

 0-358 by 0-05 mm. 



The axis is horny and flexible, in the thicker parts of a horny brown colour, in the 

 thinner parts yellowish. The colour of the ccenenchyma and of the calyx is shining 

 coral-red, that of the tentacular operculum yellow. 



This species may be distinguished from the foregoing even on external examination. 

 The secondary branches are usually ramified and arise at more acute angles. They also 

 exhibit the pinnate arrangement less distinctly than in the preceding species, where they 

 come off straight and are frequently unbranched. Moreover the difference in the thickness 

 of the twigs and branches is slight, while in Muricella perrarnosa the secondary branches 

 and the twigs are much more slender than the branches. The ramification in Muricella 

 nitida is relatively closer ; the calyces stand further apart and are more concentrated on 

 one surface of the colony. The spicules of the ccenenchyma are on an average larger and 

 recognisable even with the unassisted eye. 



Habitat. — Station 232, //^a^oHema-ground, off Japan ; depth, 345 fathoms; bottom, 

 green mud. 



Verrill's specimen is from Ebon Island, in the Central Pacific, south-west of the Ralik 

 group. 



Muricella gracilis, n. sp. (PI. XXV. fig. 7). 



The colony forms a thin, delicate little stem, ramified in one plane and rising from a 

 conical, encrusting base. One can distinguish an ascending main stem, from two sides of 



(ZOOL. CHALL. EXP. — PAIIT LXIV. — 1888.) SsS 17 



