CAMPTOPLITES 453 



Station distribution. Antarctic: Weddell Quadrant, Sts. 167, 181 1 and Deception Island; 

 Victoria Quadrant, Sts. 1652, 1660. 



Geographical distribution. South Orkney Islands; South Shetland Islands (Discovery); 

 Palmer Archipelago 1 (Discovery); Bellingshausen Sea? (Waters); Wilhelm II Land (Kluge); Oates 

 Land (Terra Nova); Ross Sea (National Antarctic Expedition; Terra Nova; Discovery). 



The shape of the colony, with straight main branches, consisting of several series of 

 zooecia, and giving off fan-shaped secondary branches at fairly regular intervals on each 

 side, is characteristic (Plate XII, fig. 3). There is commonly a secondary branch at the 

 bifurcation, arising from the axillary chamber. Ovicells (Fig. 46 A) are numerous on 

 the secondary branches. They are like those of Camptoplites abyssicolus (Kluge, 19 14, 

 text-fig. 18, p. 632), but are less reduced. 



The avicularia are very variable in size so that they do not obviously represent two 

 kinds, but two types, distinguished on p. 435, are nevertheless present (Fig. 46 D, E). 

 My specimens agree so well with Kluge 's account in other respects that I have no hesita- 

 tion in making the identification, despite his statement that the avicularia are all of one 

 form though varying in size. 



Ancestrulae which appear to belong to this species are described on p. 438 (species 6). 



11. Camptoplites retiformis (Kluge). Plate IX, fig. 3 ; Figs. 47 A-H, 48 A, B. 



Bugula retiformis Kluge, 1914, p. 629, pi. xxviii, fig. 5, text-fig. 14; Livingstone, 1928, p. 27. 



Camptoplites retiformis Harmer, 1923, p. 300. 



Station distribution. Antarctic: Weddell Quadrant, Sts. 27, 39, 42, 156, 181, 187, 190, 1948, 

 WS 33, WS 42, MS 71; Victoria Quadrant, Sts. 1652, 1660. 



Geographical distribution. South Georgia; near Elephant Island; Palmer Archipelago 

 (Discovery) ; Wilhelm II Land (Kluge) ; Queen Mary Land (Livingstone) ; Oates Land (Terra Nova) ; 

 Ross Sea (Terra Nova; Discovery). 



The appearance of the ovicells differs markedly with age. When first formed the 

 entooecium is radially striated, but a reticulate sculpture is gradually laid down, 

 eventually becoming very conspicuous. This is particularly well seen in a large colony 

 from St. WS 42 (South Georgia) which has two fertile zones (Plate IX, fig. 3). In the 

 younger zone there is a gradation from incompletely formed ovicells through complete 

 ones with radial striation to those in which the reticulation has begun to appear, but is 

 faint and delicate (Fig. 48 A). In the second zone the full sculpture is present (Fig. 

 48 B). The fertile zooecia of both zones bear the long, stout spines on one or both distal 

 corners. The spines on the non-fertile zooecia are also directed frontally, but are short 

 and slender. 



Rosette-plates are present in the outer lateral walls of the zooecia in the marginal 

 series, and the tips of the runners and of the lateral rootlets tend to be in contact with 

 them. In Fig. 47 H the tips of both runners of the axillary chamber and of three of the 

 four branches of the lateral rootlet end in this way. The connexion is so frequent that 

 it seems unlikely that it is accidental. Sometimes, too, the ends of rootlets that have not 

 run directly to a rosette-plate have turned and grown along the edge of the colony till 

 1 Only represented by the young colonies described on p. 438, species 5, no adult colony taken. 



