ASTRORHIZIDAE 55 



of mud. At MS 68 many of the specimens, though otherwise perfect, were flattened or 

 collapsed, apparently owing to the thinness of the mud wall. 



41. Pelosina fusiformis, sp.n. (Plate I, figs. 10-12). 

 Seven stations: 45, 126, 144, 148, 149; WS 28, 154. 



Test free, fusiform, one end usually more prolonged than the other and provided with 

 an extended but usually collapsed neck. Wall, firm and thick, and composed of mud with 

 or without admixture of sand grains, smooth and neatly finished. Internal cavity rather 

 small, the two walls accounting for more than half the maximum diameter of the test. 

 The inner wall of the cavity generally exhibits a number of funnel-shaped depressions 

 through which no doubt the protoplasm extrudes, although they do not extend to the 

 outer surface of the test. The cavity usually contains a sub-spherical solid mass, which 

 is the protoplasmic body containing a food mass of Diatoms enclosed in the chitinous 

 lining of the test. Colour grey. 



Length up to 2-0 mm. breadth up to 1-2 mm. 



Very common at Sts. 45, 148, frequent elsewhere. There is considerable variation in 

 the amount of sand incorporated ; at WS 28 a good deal of black sand is used, whereas at 

 St. 45 none at all. The aperture is seldom visible except in the few instances where the 

 protruding neck has resisted disintegration. 



P. fusiformis does not occur in company with P. rotundata except at Sts. 144, 148 and 

 WS 154. Fusiform specimens of Pelosina rotundata have been recorded by Egger and 

 Millett (E. 1893, FG, p. 254, pi. xi, fig. 60; M. 1898, etc., FM, 1899, p. 249, pi. iv, 

 figs. I a, b), and although their figures are not identical with the South Georgian speci- 

 mens, it is probable that they represent the same organism, which I regard as speci- 

 fically separable from P. rotundata. 



42. Pelosina variabilis, Brady. 



Pelosina variabilis, Brady, 1879, etc., RRC, 1879, p. 30, pi. ill, figs. 1-3; 1884, FC, p. 235, 



pi. xxvi, figs. 7-9. 



Pelosina variabilis, Flint, 1899, RFA, p. 266, pi. iv, fig. i. 



Thirteen stations: 27, 28, 45, 140, 143, 144, 148, 149; WS 27, 47, 154; Drygalski Fjord; MS 68. 



Frequent to common at most of the stations where it was recorded, although perfect 

 specimens are not very frequent. It often attains a large size, notably at Sts. 27, 45 and 

 148. At several stations the specimens are very narrow and elongate and the walls are 

 more smoothly finished than usual. Such specimens are evidently closely allied to 

 others which I am separating under the varietal name constricta. They are found at 

 Sts. 28, 143, 144 and 149, sometimes in company with the normal type. 



43. Pelosina variabilis var. constricta, var.n. (Plate I, figs. 13-15). 

 Five stations: 45, 126, 140, 144; MS 68. 



Test long, narrow, tapering to each extremity, broadest near the oral aperture which is 

 usually furnished with a short, distinct tube. More or less constricted at irregular 

 intervals, as many as five constrictions have been observed. There is no evidence that the 



