REPORT ON THE POLYZOA. 3 



' (1) Crista biciliata, Macgilliv. (PI. I. figs. 1, 2). 



Crisia biciliata, Macgilliv., Nat. Hist. Vict., Dec. iv. p. 37, pL xxxlx. fig. 2. 



Character. — An opposite pair of perfect zocEcia in each internode, with a third 

 intermediate aborted one between them, from which the succeeding pair or a branch 

 arises. A pair of long, jointed spines articulated to the outer part of each zooecium, 

 excepting those bearing the secondary branches. Ooecia small, much elongated, 

 pyriform, situated at the angle of a bifurcation. Zooecia 0'07 mm. in diameter. 



Habitat. — Station 135, Tristan da Cunha, 60 to 1100 fathoms, rock and shells; 

 [Williamstown, Mapleston ; Warrnambool, Watts]. 



As Mr. Macgillivray remarks (p. 38) "The aspect and general arrangement of the 

 cells are the same as in C. edwardsiana, d'Orb. There are two cells in each internode, 

 except in those from which the branches originate. The cells, as he observes, are not 

 80 long as those represented in M. d'Orbigny's figure of C. edwardsiana, and are wider 

 superiorly, and the free part is not so long, and is much more abruptly curved forwards ; 

 the ooecial cell is smaller, more elongated, and each lateral cell supports usually two, 

 but sometimes only one long-jointed spine." 



Mr. Macgillivray further remarks that he is doubtful to what species my description 

 and figures of Crisia edwardsiana (Brit. Mus. Cat., pt. iii. p. 5, pi. ii. figs. 5-8) refer, 

 and I am compelled to say that subsequent examination of the specimens from which 

 that description was chiefly drawn, some of which were from Tierra de Fuego, collected 

 by Mr. Darwin, and others from New Zealand, procured by Dr. Sinclair, has left 

 considerable doubt in my mind as to the identity of these two forms ; the latter, it is 

 highly probable, is distinct from the Patagonian CHsia edwardsiana, in which the 

 zooecia, as represented by M. d'Orbigny, are very long and erect, whilst in the New 

 Zealand species they are short and curved forwards. There is also another form or variety 

 closely approaching the New Zealand species, but in some measure intermediate between 

 that and the South American one, which may turn out to be distinct from either, and 

 to form an intermediate variety, characterised by a tendency to have two or more 

 pairs of cells in some of the internodes, and less exactly opposite. All three, ho we .-er, 

 are furnished with only a single articulated spine, which arises close below the mouth, 

 instead of low down the back as in Crisia biciliata. One character is observabl( in th« 

 New Zealand form which I have not noticed in the others, viz., that the dorsal aspect of 

 the pair of zooecia is entire, and faintly striated transversely. 



§§ b. Zooecia numerous (more than six) in each internode, alternate on the 

 two sides. Ooecia irregularly disposed, often absent. 



Crisia (pars), Auctt. 



