BULIMINIDAE 139 



regional distribution, St. 383, the most southerly limit, being in 60° 32' S, 62° 42' W. 

 The Terra Nova specimens were from 66° 29' 8" S, 166° 8' W, 1894 fathoms. 



296. Ehrenbergina hystrix var. glabra, Heron-Allen and Earland (F 165) (SG 192). 

 Four stations: 386; WS403, 505, 517. 



Only a single specimen at each station, two of which are in the Drake Strait, and the 

 others in the Bellingshausen Sea. Its rarity in this sector of the Antarctic is curious, 

 when compared with the abundance of specimens observed at Terra Nova stations in 

 the Ross Sea. Its absence from the South Shetlands and South Orkneys is also re- 

 markable, as the variety was recorded from both the Falklands and South Georgia. 



297. Ehrenbergina crassa, Heron-Allen and Earland (SG 193). 

 One station: 167. 



A single megalospheric specimen was found at St. 167 in the South Orkneys. In view 

 of the abundance of the species in South Georgia, I am inclined to the view that this 

 specimen may be a stray, and that the species is confined to South Georgia. It has such 

 a striking appearance that it could hardly have been overlooked if present in the 

 Antarctic material. 



298. Ehrenbergina parva, sp.n. (Plate VI, figs. 28-32). 



Sixteen stations : 175, 180, 181, 186, 195, 196, 200, 202, 203, 209; WS 382, 393, 395, 476, 482, 487. 



Test biserial, consisting of about 4-6 pairs of chambers rapidly increasing in size; 

 commencing with a spiral curve and continuing growth in a straight line, presenting 

 well-marked differences between the dorsal and ventral sides. Wall of the test rather 

 thick, coarsely perforated, the perforations giving a granular appearance to the test. The 

 chambers become increasingly inflated towards the aperture, which is a loop-like slit 

 set obliquely on the inner face of the final chamber, but sometimes almost terminal. 

 The sutural lines are depressed, particularly on the ventral side. On the dorsal side, 

 which is flatter than the ventral, the sutural lines are distinct, but almost flush. 



The aboral extremity of the shell displays a prominent knob on the ventral side of the 

 test, which contains the earliest chambers. In the megalospheric form this knob is 

 rounded and contains a large proloculus, under and behind which are the first pair of 

 chambers, growth then continuing in a straight series of 3-4 pairs of chambers. In the 

 microspheric form a very small proloculus is followed by a complete spiral curve of 

 minute chambers, about three pairs, after which there is a rapid increase in size of the 

 chambers of the straight series. The initial series forms a wedge-shaped protuberance 

 on the ventral side of the microspheric shell. 



In structure E. parva is almost identical with E. crassa, but presents well-marked 

 distinctions. In size it is comparatively minute ; there is no very great difference between 

 the sizes of the megalospheric and microspheric forms as there is in E. crassa ; the two 

 forms are practically identical in number, whereas in E. crassa the microspheric form is 

 comparatively rare ; the proloculus in the megalospheric form is smaller in proportion to 

 the size of the test, and never forms such a prominent feature as in E. crassa ; finally the 

 surface of the test is roughly granular on the exterior in contrast with the glassy smooth- 



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