TEXTULARIIDAE 105 



16, 20, 136, WS 27, 33, 48 and 418, elsewhere generally rare to very rare. Both megalo- 

 spheric and microspheric specimens are found, wherever it is present in any numbers. 

 Nowhere does it attain such size as in the Falkland area ; the best specimens were at 

 WS 33 and 42. 



Genus Ehrenbergina, Reuss, 1850 



191. Ehrenbergina pupa (d'Orbigny) (F 164). 

 Five stations: 30, 149; WS 25, 27, 33. 



The extreme rarity of this species round South Georgia as compared with its abun- 

 dance in the Falkland area is most marked, and points to the fact that it has not succeeded 

 in establishing its footing in the colder water. It is moderately frequent at WS 27 

 which is off the north-west corner of the island and therefore on its line of approach 

 from the Falkland area. At the remaining stations the species is represented by one or 

 two specimens only. 



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

 Five stations: WS 33, 51, 66, 314, 418. 



This Antarctic form is common at WS 51, but the specimens are rather small though 

 typical. At all the other stations it is very rare, but the few specimens found were 

 generally large, though often weakly developed as regards the marginal spines. 



193. Ehrenbergina crassa, Heron-Allen and Earland (Plate VI, figs. 1-9). 



Ehrenbergina crassa, Heron-Allen and Earland, 1929, etc., FSA, 1929, p. 329, pi. iii, figs. 18-26. 



Fifty stations: 13, 14, 20, 23, 27, 28, 30, 31, 41, 42, 45, 123, 126, 131, 136, 140, 143, 144, 148, 149, 

 157, 660; WS 20, 25, 27,28,32, 33,37,40,41,42,43,45,46,47,48, 50, 51, 52, 66, 113,154, 314, 

 348. 349. 357, 418; MS 14, 68. 



Test very thick-walled throughout, finely perforate, hyaline in the younger stages, but 

 frequently becoming white and semi-opaque in the adult shell. Constructed of a 

 variable number of chambers regularly increasing in size, arranged biserially about an 

 elongate axis and presenting well-marked dorsal and ventral sides. The main axis of the 

 shell is normally straight, but occasionally exhibits a spiral tendency, thus giving a 

 virguline appearance to such tests. The dorsal side of the test is flatter and wider than 

 the ventral, and the sutural fines, which are depressed, are more prominent on the 

 dorsal side owing to their greater thickness. 



The sutures are most noticeable in the oral half of the shell, those of the initial half 

 being usually more or less obscured by a secondary layer of shell substance which is 

 sometimes granular or even feebly striated. The oral half of the shell is quite smooth 

 and devoid of ornament. The aperture is a loop-like sfit set obliquely on the inner face of 

 the final chamber. 



The initial portion of the shell consists of a more or less prominent knob, curved 

 over towards the ventral side and excentric to the main axis of the shell. In the megalo- 

 spheric form, this knob is very prominent, and contains the proloculum situated on its 

 ventral face, behind which is the first pair of chambers. In the microspheric form, it 



