768 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 14 



to 2 mm and a diameter of as much as 0.80 mm. In other parts of the 

 sub-colony the bulbs are much smaller, from 0.40 to 0.65 mm high and 

 from 0.13 to 0.26 mm in diameter. 



The erect branches should be homologous with the stalks of other 

 barentsias, but they differ in bearing a series of zoids throughout their 

 length without joints or septa; they appear like erect stolons, except for 

 the large muscular basal bulb. These erect stems bear branches, all in 

 the same plane, up to the fifth generation of zoids. The unbranched 

 internodes are comparatively short, usually less than 1.0 mm and about 

 0.08 mm in diameter. The calyx is similar to those of other barentsias, 

 0.40 to 0.50 mm high by 0.35 to 0.40 mm in width. 



The unusual features of this species are the large size and complexity 

 of the colony, the nature of the branching, the absence of nodes, and the 

 variation in the size of the basal bulbs. 



Known only from Kluge's record (Drifting Ice Expedition in the 

 central Arctic Ocean in the Ice-breaking Str. "G. Sedov," 1937-40). 



Point Barrow, Alaska, Arctic Research Laboratory, 246 feet, G. E. 

 MacGinitie, collector, several colonies. 



J ^^^ 



^ *.l— *- Barentsia robusta new species 



Plate 82, fig. 7 



The stolon adnate, ramifying, 0.08 mm wide. The individual zooecia 

 are short-stalked with large calyces, reaching a total height of about 2 

 mm. The stalks are disproportionate, as the basal bulbs are longer than 

 the narrow internodes. The basal muscular bulbs are unusually long 

 and measure rather regularly 0.90 mm in height by 0.18 mm in diameter. 

 The internode is 0.70 to 0.78 mm long; at the base it varies from 0.06 

 to 0.08 mm wide and gradually enlarges to 0.11 to 0.13 mm in diameter 

 at the top ; the internode wall is moderately chitinized and its inner 

 layer is punctured by scattering conspicuous "pores," similar to those 

 of B. discreta but larger and much fewer in number. The calyx is large, 

 the height to the base of the tentacle ring as much as 0.65 mm, and its 

 width varying from 0.52 to 0.65 mm, cup-shaped, widest at the top and 

 the base rounded, the dorsal side curved, the ventral side much straighten 

 The tentacles cannot be counted accurately but apparently they number 

 about 20 to 24. 



The larger calyces all contain embryos in August. The stout appear- 

 ance of the zooecia, all about the same height, the large calyces (nearly 

 one third of the total height) and the very long and comparatively 

 slender basal bulbs which are consistently longer than the internodes, 



