TIEPORT ON THE ALCYONARIA. 131 



The axis is thin, horny, flexilile and of a brown colour. The coenenchyma and calyces 

 are of a beautiful coral-red colour, corresponding to the intense red colour of the spicules. 

 The tentacular opercula are whitish. 



Habitat. — Admiralty Islands; depth, 16 to 20 fathoms. 



Muricella crassa, n. sp. 



Colony upright and ramified in one plane, with thick coenenchyma, from which the 

 bluntly conical polyps stand out straight, arranged in spii-als. The branches and twigs 

 are thickened at the apex. 



The entire habit recalls Paramnricea placomus (Esper). 



The main stem rises from a flat, expanded base to a height of 300 mm., with a 

 thickness of 6 mm. wdiich remains tolerably uniform throughout its course. Already at 

 the base a branch, which has the same thickness as the main stem, comes otf at an angle 

 of 45°, and reaches a length of 130 mm. From this, as from the main stem, lateral 

 brandies come oif on two sides, and finally bear twigs up to the third order. All are 

 of nearly the same thickness ; the terminal points are blunted and expanded (5 to 6 mm.). 

 The branches and twigs arise at wide distances from one another ; the terminal twigs 

 attain a length of 70 mm. 



The coenenchyma is very thick and contains several layers of calcareous spicules. 

 The horny, flexible axis is relatively thin and weak, being 1 mm. thick in twigs which 

 have a diameter of 5 mm. The polyps project vertically from the coenenchyma at 

 intervals of from 1 to 1'5 mm., arranged in close, irregular spirals. The calyx forms a 

 truncated cone, measuring 2 to 2 "5 mm. at the base and 2 mm. high. The tentacular 

 operculum can be withdrawn within the mouth of the calyx, but in the spirit specimen it 

 forms on most of the calyces a low pyramid projecting above the calyx mouth. The apex 

 of each twig is occupied by a short process of the coenenchyma, on which are placed three 

 polyps standing out in diflerent directions. 



The spicules of the coenenchyma are large, stout spindles which are usually slightly 

 curved. Sometimes they appear blunt at both ends, sometimes pointed at one end and 

 rounded ofl' at the other, but always covered with very closely placed, granular warts, 

 which stand out straight. On the surface they form a thick layer. In the deep part of 

 the cqeuenchyma they are smaller and fretpently possess one to three outgrowths, which 

 indicate double to quadruple formations. They measure r2 by O'l ; 1 by 0-26 ; 0-9 by 

 0-25 ; 1-2 by O'lS ; 0-9 by 0-125 ; I'l by 0-2 ; 0-62 by 0-083 ; 0-5 by 0-38 mm. The 

 two last are double and quadruple spicules in which the breadth is the expansion of the 

 lateral rays. 



In the calyx the spindles form only one layer and are arranged in eight longitudinal 

 bands, which stand vertically upon the spicules of the coenenchyma. Each of the bands 



