rOEAMINIPERA OF THE KERIJVIBA AECHIPELAGO. 695 



353. Discorbiiia tuberculata Balkwiil & Wright. 



IHscorbina tuberculata Balkwiil & Wright, 1885, DIS. p. 350, pi. xiii. fiprs. 28-30. 

 Sidebottom, 1904, etc., RED. 1908, p. 15, pi. v. fig. 5. 

 Heron-Allen & Earland, 1913, CI. p. 127. 



1 Station. 



One typical specimen from Stn. 11. 



354. Discorbina araucana (d"Orbigny). 



f'osalinii uraiicana d'Oi'bigny, 1839, FAM. p. 44, pi. vi. figs. 16-18. 

 Discorbina araucana Brady, 1884, FC. p. 645, pi. Ixxxvi. tigs. 10, 11. 



Egger, 1893, FG. p. 386, pi. xiv. figs. 4, 6. 



Chapman, 1900, FLF. p. 190. 



Sidebottom, 1904, etc., RFD. 1908, p. 12. 



Heron-Allen & Earland, 1908, etc., SB. 1911, p. 327. 



1 Station. 



A few specimens only, wliich appear to be referable to this somewhat weak 

 representative of the I), rosacea group. 



355. Discorbina valvulata (d'Orbigny). 



liosalina valvulata d'Orbigny, 1826, TMC. p. 271. no. 4. 



d'Orbigny, 1839, FIC. p. 136, pi. ii. figs. 19-21. 

 Discorbina valvulata Jones & Parker, 1872, FFR. p. 114. 



Brady, 1884, FC. p. 644, pi. Ixxxvii. figs. 5-7. 



EggeV, 1893, FG. p. 392, pi. xv. figs. 64-66. 



Chapman, 1907, RFV. p. 137. 



2 Stations. 



A few poor specimens at Stn. 1, the sutures being very feebly limbate compared 

 with the type; stronger and better specimens at Stn. 11. 



356. Discorbina valvulata, var. granulosa, n. (Pi. Lll. figs. 1-6.) 



2 Stations. 



Test nearly circular in outline, closely resembling I), valvulata, but with the 

 superior surface thickly encrusted with secondary shell-matter rendering the septation 

 and sutural lines very obscure. Under surface showing five to six inflated chambers 

 separated by strongly limbate sutures and with a mass of secondary shell-matter in 

 the umbilical depression. Coarsely perforated on the superior side, but no per- 

 forations visible on the inferior side. Colour a rich pale brown, lightening towards 

 the final chambers and colourless on the inferior side. 



This curious but very distinctive variety occurs very rarely at Stn. 11, and a single 

 specimen at Stn. IX. The granulation renders the variety easily distinguishable 

 from d'Orbigny's type, Bosalina valvulata (d'O. 1839, FIC. p. 136, pi. ii. figs. 19-21). 



Size very variable — specimens range between -25 and -45 mm. in greatest diameter; 

 height of largest specimen '32 mm. 



VOL. XX. — PART xvii. No. 20. — November, 1915. 5 e 



