REPORT ON THE ALCYONARIA. 133 



specimen there can be little certainty. According to Dr. Gray's description the " Coral 

 stem is free, filiform, simple, rather rigid," &c., but there seems no reason to suggest 

 that the axis of the form now described was otherwise than fixed. 



Elasmogorgiajiliformis, n. sp. (PI. XXIII. fig. 10; PI. XXVII. fig. 7). 



The colony consists of a long, flexible, thin, little stem, which is very slightly 

 thickened at what is pretty certainly the terminal end ; the base is wanting. Towards 

 the upper part a simple branch is given ofi" at an acute angle, which is not longer than 

 the principal stem. The length of the principal stem, so far as preserved, is 270 mm., 

 with a diameter, in the lower portion, of 1 mm., and of 1"5 mm. at its apex. The 

 lateral branch is 30 mm. long. The coenenchyma is thin but not transparent. The 

 polyps arise at right angles from the somewhat flattened stem, at long intervals and for 

 the most part from either side, in alternating series. Directly under the truncated apex 

 of the stem, which has small polyps, three polyps stand nearly in one plane. The polyps 

 in the lower part of the stem are somewhat cylindrical ; towards the top they are more 

 conical, with a round oral region; their basal diameter is 1 mm., with a height of 

 0"5 mm. The tentacular operculum in a retractile state is quite withdrawn into the 

 calyx. The spicules are broad spindles, armed with small sharp spines, which in the 

 coenenchyma are placed close to one another, and are frequently curved. They 

 constitute a thick uniform layer. In the coenenchyma they are placed in the longi- 

 tudinal direction of the stem ; on the body of the polyp they are placed circumferentially, 

 beginning from the base. They are of considerable size, so that they are discern- 

 ible on a very slight enlargement. They measure, length by breadth, 0'62-0"13 ; 

 0-5-0-1 ; 0-33-0-08 ; OlS-O-l ; 0-23-0-07 mm. The basal portions of the tentacles are 

 armed with numerous spindle-shaped spicules, which measure from 0'18 to 0'16 mm. in 

 length, and from 0"04 to 0"016 mm. in breadth. The axis is thin, horny, black, and 

 flexible. The colour of the stem is white. 



Habitat.- — Station 188, Arafura Sea, south of Papua; depth, 28 fathoms; bottom, 

 green mud. 



Genus Muricea, Verrill {emend.). 



In the genus Muricea Lamouroux included all the then known species of Muriceids ; 

 KoUiker was the first to greatly limit it,^ by separating from it the species which form 

 the genera Paramuricea, Echinogorgia, &c., in which spindle-shaped and unilateral 

 spiny spicules occur. Verrill ■ still further circumscribed the genus, and divided 

 KoUiker's group into three, Eumuricea, Muricea, and Muricella. These three groups 



' Icones Histiologicae, p. 135. ' Trans. Connect. Acad., vol. i. p. 449. 



