EEPORT ON THE ALCYONARIA. xlvii 



probably represents that on which the colony rests. The apex of the colony consists of'a 

 pointed, knob-like stolon, which bears no polyp. The polyps are covered with large, 

 imbricate scales, of which those of the last row are continued into long spine-like 

 processes. The operculum of eight scales is well developed. Twelve longitudinal canals 

 surround the axis ; these increase in diameter towards the ventral groove. They are 

 symmetrically arranged at either side of an axis represented by a line drawn at a right 

 angle from the middle of the ventral groove to the opposite region of the periphery. 



1. Callozostron, Perceval Wright, Narr. Chall. Exp., vol. i. p. 691, 1885. 

 The diagnosis of the subfamily will serve for the genus. 



Subfamily 2. Calyptrophorin.^. 



Cahjptroplioradse, Gray, Cat. Lithophytes Brit. Mus., p. 41, 1870. 



Colony usually branched ; the calyces bilaterally symmetrical, enclosed within scales ; 

 eight scales compose the operculum. Two scales guard the base of the polyp, and above 

 these there are two others which surround the calyx and are articulated with one another. 

 The first of these, which rests on the two basal scales, is externally broad and high, the 

 margins are sometimes continued into divergent spines, while internally the edges narrow 

 and turn inwards so as to form a ring around the ventral aspect of the polyp. The second 

 is attached to the internal margin of the former, it is also much broadened externally 

 and often toothed, while internally it also forms a narrow ring. The upper scale can be 

 bent inwards at an angle upon the lower. The opercular pieces are symmetrically 

 distributed on the dorso- ventral plane, so that the dorsals, those furthest from the stem, 

 are the largest, and the ventrals the smallest. 



2. Calyptrophora, Gray, Proc. Zool. Soc. Lond., 1866, p. 25 ; Gray, Cat. Lithophytes 



Brit. Mus., 1870, p. 41 ; Studer, Monatsber. d. k. preuss. Akad. d. Wiss. 

 Berlin, 1878, p. 642. 



The diagnosis of the subfamily may suffice for the genus. 



Subfamily 3. Primnoin^. 



The colonies are of variable form, sometimes simple, sometimes branched. The 

 polyp calyces are mostly bilateral ; the dorso-ventral axis is directed at right angles to 

 the longitudinal axis of the stem. The polyp calyces can be bent inwards towards the 

 stem, and are often at the same time twisted upon their bases. "The individual calyx 

 scales never surround the entire periphery of the calycine portion, but there are at 

 least two in each transverse girth. The larger scales form the dorsal and lateral wall 



