ROTALIINAE 415 



349. Discorbis parisiensis (d'Orbigny). 



Rosalina parisiensis, d'Orbigny, 1S26, TMC, p. 271, Modele no. 38. 



Discorbina parisiensis, Parker, Jones and Brady, 1866, etc., MFC, i866, pi. ii, figs. 13-15 ; 1896, 



p. 296. 



Discorbina parisiensis, Brady, 1884, FC, p. 648, pi. xc, figs. 5, 6, 9-12. 



One station : WS 88. 



Two small but fairly typical specimens at this station. 



350. Discorbis obtusa (d'Orbigny) (Plate XIV, figs. 19-21). 



Rosalina obtusa, d'Orbigny, 1846, FFV, p. 179, pi. xi, figs. 4-6. 

 Discorbina obtusa, Brady, 1884, FC, p. 644, pi. xci, fig. g a, b, c (?). 

 Discorbina obtusa, Cushman, 1918, SFP, p. 68, pi. xiii, fig. i. 



One station: WS 88. 



A few excellent and typical specimens, identical with the Type in Paris. Breadth, 

 0-25 mm. Height, 0-15 mm. 



351. Discorbis malovensis, sp.n. (Plate XIV, figs. 22-24). 

 Four stations: WS 71, 86, 88, 89. 



Test circular, plano-convex, very finely perforate and polished ; consisting of three or 

 four convolutions each containing four (rarely five) narrow recurving chambers, in- 

 creasing rapidly in size: peripheral edge entire (unbroken), subacute; dorsal surface 

 highly polished and exhibiting all chambers, sutures recurved, flush but distinct; 

 ventral side, nearly flat, slightly sunk at the umbilicus, only the chambers of the final 

 convolution visible, sutures recurved and rather depressed, distinct round the peri- 

 pheral edge but largely obscured by a secondary deposit of beads covering all but the 

 final chamber and the outer margins of the preceding chambers ; aperture a curved slit 

 under the anterior edge of the final chamber; colour yellowish to glassy white. 



Dimensions up to 0-40 mm. in diameter; height about o-io mm. 



A few specimens only from each Station, the best at WS 71, 86, 88. Many of them 

 show signs of plastogamy but no actual pairs were seen. 



The species is closely allied to D. plana sp.n. (No. 342) with which its distribution 

 practically agrees, all the stations being confined to the southern areas. It diflFers from 

 D. plana in its greater convexity, in the dome-like smoothness of the dorsal surface, and 

 in its unbroken peripheral margin. 



D. malovensis is allied both to D.pileolus (d'Orbigny) and to the very difl^erent organism 

 figured by Brady under the name D.pileolus (d'Orbigny) (B. 1884, FC, p. 649, pi. Ixxxix, 

 figs. 2-4) and generally associated since with d'Orbigny's species. But it difi^ers from 

 Brady's organism in many features, notably in the lesser number of chambers to the 

 convolution and its highly polished dorsal surface. The organism figured by Brady is a 

 well known type in the Indo-Pacific Region and is of frequent occurrence in the New 

 Zealand and Australian area. In the Northern Pacific it appears to be replaced by a 

 somewhat similar organism which is found on American shores and has been described 



