3 86 DISCOVERY REPORTS 



As in many specimens of C. darwinii, there are many moderately enlarged frontal 



avicularia. 



Hasenbank's figure shows all these peculiarities and clearly represents this variety. 

 He recorded C. boryi from four South African stations, and he has kindly informed 

 me that the figured specimen came from St. 114, which was in Simon's Bay at 70 m. 

 Challenger St. 142, on the other hand, was on the edge of the continental shelf (see 

 p. 384). 



Although this variety shows some resemblance to C. boryi, I am satisfied that its 

 affinities are with C. darwinii. It differs from C. boryi in its extensive, granular crypto- 

 cyst, in the absence of an oral bar, in the large vibracula which almost completely cover 

 the basal surface, in the absence of giant frontal avicularia and the presence of many 

 moderately enlarged ones. In all these respects it resembles C. darwinii, particularly 

 specimens of the Swain's Bay type. In the part played by the cryptocyst of the outer 

 side of the opesia in the formation of the proximal lip of the orifice, it far exceeds 

 C. boryi, and in this respect it is distinct from both C. boryi and C. darwinii. In C. boryi 

 the outer cryptocyst forms less than half the lip and widens towards the orifice to do so 

 (see Fig. 19 B and Harmer, 1926, pi. xxiv, fig. 13). In var. occlusa the cryptocyst forms 

 fully three-fourths of the lip, although it is little, if at all, wider in that part. The varia- 

 tion of typical C. darwinii shows that size may be of little systematic significance, but it 

 should be mentioned that the zooecia of var. occlusa are larger than those of C. boryi 

 (cf. Figs. 19 A and 22 D in which the difference in size is quite marked despite the 

 greater magnification of the drawing of C. boryi). 



The original drawing of fig. 6 b in the Challenger Report is accompanied by a sketch 

 of the whole colony (reproduced in the Report as fig. 6a) which can be recognized as 

 representing the colony now made the type of var. occlusa. This indication of the identity 

 of the specimen figured by Busk is confirmed by the fact that the actual branch shown 

 in fig. 6b can be recognized from the accuracy with which certain details are drawn. 

 Despite this, the drawing of the scutum and cryptocyst is inaccurate and shows none of 

 their peculiarities. My Fig. 22 D is drawn from the same specimen. 



6. Caberea darwinii var. guntheri var.n. Plate VI, fig. 4; Fig. 24 B. 



Station distribution. Sub- Antarctic : South Atlantic Ocean, Sts. WS 840, WS 871. 

 Geographical distribution. Off Patagonian Shelf, below 336 m. (Discovery). 

 Holotype. St. WS 840. 



These specimens differ from typical C. darzvinii in the presence of gigantic avicularia, 

 placed proximally to many of the bifurcations, the other frontal avicularia being small 

 (Fig. 24 B). The gigantic avicularia have a broad mandible, and the avicularian chamber 

 spreads proximally over the peduncles of the scuta of neighbouring zooecia, forming 

 lobes of which the more proximal is usually long and pointed. The extensive cryptocyst 

 is finely and evenly granular as seen in dry specimens, but may appear almost smooth in 

 a balsam preparation. 



In the relatively luxuriant growth of the colonies (Plate VI, fig. 4), in the large size 



