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



The spicules measure 0-3-0 -02 ; 0-28-0-03 ; 0-2-0-025 ; 0-15-0-025 ; 0-12-0 "04 mm. 



The colour of the colony in spirits is a greyish-white. 



Habitat. — Station 151, off Heard Island; depth, 75 fathoms. 



A quite similar form, but probably a young colony, was found by Studer at the 

 Cascade Ridge, N.E. Kerguelen, also on the stem of a Macrocijstis ; its colour in life was 

 noted as " pale red" ; the specimen has been lost. 



Alcyonium sollasi, n. sp. (PI. XLII. fig. 4). 



The colony presents a more or less lobulate form, which is attached to, and embedded 

 in, a mass of hardened sand and mud. One colony measures about 75 mm. in its widest, 

 and 65 mm. in its narrowest diameter, and is about 45 mm. in height. Another measures 

 90 mm. in length, by about 60 mm. in width, and is about 40 mm. in height. The l)asal 

 attachment is but little wider than the rest of the colony, and only a very narrow rim 

 is destitute of polyps. The lobes are sometimes simple, at other times they are bifid or 

 trifid ; they are short, papilliform, not finger-like ; they often grow very tightly against 

 one another, thus altering their original shape. 



The polyps are numerous and very closely packed together ; they are completely 

 retractile within the body-cavities, and when withdrawn, the basal portion next to the 

 ccenenchyma is drawn together and over the retracted portion, forming eight protuber- 

 ances, which make an eight-rayed star. In dried specimens these slightly project above 

 the coen'enchymal surface, and are from 1-.5 to 2 mm. in diameter. 



The spicules of the ccenenchyma are, for the most part, stachelkeuleu. These form a 

 continuous layer on the outer surface of the colony, giving it a well-marked consistency. 

 In addition there are spiny spindles, both straight and bent, and also some spiny spindles 

 with broad, spiny heads, resembling, but difi'erent from, the stachelkeulen. 



The spicules measure : — The stachelkeulen 0*2-0-0 ; 0-16-0-06 ; 0-12-0-08 mm. 

 The straight spiny spindles 0-22-0-04 ; 0-3-0-08 ; 0-4-0-06 mm. The curved spiny 

 spindles 0-34-0-04 ; 0-34-0-06 mm. The spiny spindles with spiny heads 0-26-0-06 ; 

 0-22-0-04. 



Colour in spirits, light brown. 



Habitat. — Station 313 ; entrance to the Straits of Magellan ; depth, 55 fathoms. 



Alcyonium liaddoni, n. sp. (PI. XLII. fig. 6). 



In this species the colony forms very variously shaped and sized masses, which grow 

 over the dead stems of a species of Muriceid. In one specimen the colony consists of a 

 but slightly elevated mass, about 40 mm. in length, by about 10 mm. in its widest 

 central diameter ; it is growing around the axis of a Muriceid. The edge of the colony. 



