3s6 DISCOVERY REPORTS 



roughened. Colour nearly white but the earlier chambers are often brownish. The 

 perforations are extremely minute. 



Length, o-27-o-3i mm.; breadth, o-ii-o-i2 mm.; thickness, o-o6 mm. 



The distribution of B. malovensis appears to be confined to the southern area of the 

 Falklands. It is not uncommon at those stations where it occurs, the best of the 

 specimens being recorded from WS 71 , 88 and 89. There is little variation except in the 

 lobulation of the edge and the slightly roughened surface.. 



154. Bolivina cincta, sp.n. (Plate IX, fig. 16-18). 



Fourteen stations: 228, 230, 235, 236; WS 76, 88, 93, 97, 221, 245, 248, 408, 409, 433. 



Test leaf-shaped, the length being usually about double the breadth; compressed on 

 both sides, consisting of about 5-7 pairs of flattened chambers separated by very strongly 

 limbate sutural lines; marginal edge somewhat thickened, broad and flat, slightly 

 recessed at each chamber; surface of the chambers between the limbate sutures, 

 roughened and opaque, becoming smooth and more translucent in the final chambers. 

 Aperture a large slit on the final chamber. Colour dirty white, opaque except at oral end. 



Length, 0-25 mm.; breadth, 0-15 mm.; thickness, 0-03 mm. 



This little species is widely distributed in the Falkland area but never very common. 

 Most numerous and best at 228 and WS 245 and 408. Two distinct forms varying in 

 length and breadth are found at most stations ; the short, broad form is mostly about half 

 the size of the larger, narrower form. There is no difl^erence in their external appearance, 

 and the proloculum is apparently identical. There is a certain amount of variation in the 

 strength of the limbation, which may entirely disappear from the later chambers, but 

 the species is, as a whole, very uniform and characteristic. 



155. Bolivina rhomboidalis (Millett). 



Textidaria rhomhoidalis, Millett, 1898, etc., FM, 1899, p. 559, pi. vii, fig. 4. 

 Textidaiia rhomboidalis, Sidebottom, 1904, etc., RFD, 1905, p. 8, pi. ii, figs. 2, (?)3. 

 Bolivina rhomboidalis, Cushman, 1922, FTR, p. 28. 



One station: 51. 



A single typical specimen was found at 51 which is close to the north shore of the 

 islands. Its presence is difficult to account for, as it is believed that the precautions 

 taken to prevent fouling of sieves are sufficient to ensure it not having been derived from 

 a distant locality. 



The species is of frequent occurrence in the tropical and sub-tropical Indo-Pacific 

 region, in the Mediterranean, and more rarely in the West Indies and tropical Atlantic. 



Genus Bifarina, Parker and Jones, 1872 



156. Bifarina porrecta (Brady). 



Bolivina porrecta, Brady, 1879, ^^c., RRC, 1881, p. 57; 18S4, FC, p. 418, pi. Hi, fig. 22. 

 Bolivina (Bifarina) porrecta, Cushman, 1918, etc., FAO, 1922, p. 39, pi. vii, fig. 2. 



Two stations: WS 408, 531. 



A single good specimen of this common North Atlantic form at each station. 



