GEOGRAPHICAL DISTRIBUTION 477 



Opesia triangular, acutely pointed proximally, a little less than half the length of the 

 zooecium. Orifice distal. 



Avicularium rigidly attached, erect, with beak directed away from axis of branch. 



Ovicells unknown. 



Remarks. About forty zooecia of this species were found in a jar of mixed fragments 

 of several species all in a very brittle state. In most instances one or other of the two 

 distal zooecia has been broken off, but they have left signs of breakage which leave me 

 with no doubt that the triple arrangement, in which each zooecium supports a median 

 distal zooecium, a distal lateral zooecium and a distal lateral avicularium, is typical. This 

 species differs from Brettia inornata in the presence of avicularia, in the longer opesia, 

 in the more pronounced shoulders supporting the lateral distal zooecium and avi- 

 cularium and in the formation of median distal buds. There can be little doubt that the 

 two forms are congeneric, and I have put them provisionally into Brettia, although the 

 avicularia of B. triplex may ultimately exclude them from that genus. More material 

 of B. triplex is very desirable. 



These two species show some resemblance to Maplestonia simplex MacGillivray 

 (1885, p. 107, pi. i, figs. 2, 2a, zb = Brettia simplex Levinsen, 1909, p. 113, pi. iv, 

 fig. 9 a, b), but not to the genotype of Maplestonia, M. cirrata MacGillivray. 



GEOGRAPHICAL DISTRIBUTION 



This report deals with so small a proportion of the Antarctic Polyzoa that their 

 distribution cannot profitably be compared with that of other groups. The facts of the 

 distribution of the species and genera considered in the report may, however, be use- 

 fully summarized. 



DISTRIBUTION OF THE SPECIES 



The distribution of the Antarctic and sub-Antarctic species of the families dealt with 

 is given in Table 3. The Antarctic and sub- Antarctic areas are taken as the region south 

 of the subtropical convergence (see map, Fig. 59). The subtropical convergence curves 

 northwards in the south-eastern Pacific and goes off this map. Gunther (1936, p. 236) 

 found it along the 30-32 S parallels in 95-105 W ; and in 70-71 ° W, nearer the Chilean 

 coast, it was as far north as 24-26 S. Thus Juan Fernandez and Valparaiso come within 

 the sub-Antarctic area hydrologically. This is in keeping with the relationship between 

 the faunas of Juan Fernandez and the Magellanic region discussed by Marcus (1921a, 



PP- 93-5)- 



In Table 3 the non-abyssal localities are grouped regionally as follows: (1) Austra- 

 lasian, (2) South Pacific, (3) South Atlantic Ocean, (4) South Indian Ocean, (5) Weddell 

 Quadrant (plus Bouvet Island), (6) Victoria Quadrant. The localities are arranged from 

 north to south except in the Victoria Quadrant where they are arranged from east to 

 west. The abyssal stations, both Antarctic and sub-Antarctic, are all treated together 

 in the last column. The South Pacific column includes Challenger St. 308 which is in 

 320 m. and is comparable with the stations off the Patagonian shelf (see p. 486). The 

 order of the species is designed to group together those with similar distribution. 



D XXII 23 



