CABEREA 389 



process at the base of the stalk, which is well developed in var. guntheri, is absent in the 

 Juan Fernandez species. 



7. Caberea angusta sp.n. Fig. 25 C, D. 

 Station distribution. New Zealand: Sts. 934, 935. 

 Geographical distribution. New Zealand (Discovery). 

 Holotype. St. 935. 



Description. Colony with branching and joints typical of genus. Rootlets calcified. 



Branches rather stout, biserial, strongly keeled basally, rather broad and flat frontally 

 (Fig. 25 D). 



Zooecia usually with two distal spines (one outer, one peduncular), peduncular spine 

 frequently hidden by or fused to frontal avicularium (Fig. 25 C). Aperture occupying 

 whole frontal surface (no frontal gymnocyst). Cryptocyst wide, extra wide proximally 

 when proximal zooecium fertile. No apertural bar. 



Scutum meeting stout hooked process from opposite border of aperture. Distal lobe 

 blunt, proximal lobe covering aperture, with a point towards stalk. 



Frontal avicularia small and directed distally when distal to an ovicell, otherwise 

 moderately large, with long mandible directed obliquely backwards. 



Marginal avicularia very small (Fig. 25 D). 



Vibracula large, oblique and in close contact with each other. 



Ovicells small, narrow, springing from little more than half distal border of orifice of 

 fertile zooecium, leaving about two-thirds of width of cryptocyst of distal zooecium 

 uncovered between ovicell and margin of the branch (Fig. 25 C). 



Remarks. C. angusta differs from all other species of Caberea known to me in its 

 narrow ovicells which spring from about half the distal border of the orifice and occupy 

 the middle of the branch. In other ways it may be compared with C. darwinii which it 

 resembles in its wide cryptocyst and the connexion of the scutum with the cryptocyst. 

 It differs in the large size of the vibracula in proportion to the zooecia, the vibracula 

 being larger than those of the Antarctic type of C. darwinii, the zooecia rather shorter 

 than those of the Swain's Bay type, but broad. It follows that the vibracula have to lie 

 more obliquely, are in close juxtaposition, and form a pronounced keel (cf. Figs. 21 C 

 and 25 D). The frontal surface, on the other hand, is flat. The frontal avicularia have a 

 longer narrower mandible, and, in the absence of ovicells, form an almost continuous 

 zigzag series down the middle of the branch. The point on the proximal lobe of the 

 scutum also distinguishes C. angusta from C. darwinii. 



8. Caberea rostrata Busk. Fig. 25 A, B. 



Caberea rostrata Busk, 1884, p. 28, pi. xxxii, fig. 4 a-d; Livingstone, 1929, p. 54. 



not Caberea rostrata Marcus, 1921a, p. 95, text-fig. 1 a, b. 



not Caberea rostrata Waters, 1887, p. 90. 



Station distribution. Sub- Antarctic: South Atlantic Ocean, Sts. 4, 5, 1187. 



Geographical distribution. New Zealand (Busk; Livingstone; Terra Nova); Tristan da Cunha 

 (Discovery). 



