FOEAMINIFEEA OF THE KEEIMBA AECHIPELAGO. 725 



431. Gypsina inhsBrens, var. plana (Carter). 



Polyirema planum Carter, 1876, P. p. 211, pi. xiii. figs. 18, 19. 

 Gypsina melobesioides Carter, 1880, etc., SG-M. 1880, p. 445. 

 Pulytrema planum Chapman, 1900, FLF. p. 201, pi. xx. figs. 6, 7. 



„ „ Chapman, 1901, FFA. p. 396, pi. xxxv. figs. 2, 4. 



Gypsina plana M. Lindsey, 1913, " On Gypsina plana, Carter, and the Relations of the Genus," 

 Trans. Linn. Soc. Lend. (Zoology), ser. 2, vol. xvi. pp. 45-51. 



5 Stations. 



This wild-growing and exuberant variety, which is characterized by the abnormally 

 large size of the individual chamberlets and by the coai'se perforation of the thick 

 shell-wall, often masked by a deposit of granular shell-substance, occurs at sevei*al 

 Stns., notably Stns. 3, 10, 11, 12, and % X. None of the specimens is perfect, all 

 representing fragments of a much larger organism which has in nearly all cases been 

 attached to some foreign body. In a few instances specimens in the attached state 

 were found. The character of our material, which represented only the finer siftings 

 of Dr. Simpson's dredgings, is doubtless responsible for the absence of perfect 

 individuals, but judging from the fragments, many of which are \ inch and upward in 

 diameter, the perfect colonies must have attained very large dimensions. As previously 

 noted, we see no reason for separating these specimens from the normal G. inhoerens 

 except for facility of reference ; the mere difference in the size of the chambers can 

 have no biological significance, beyond marking exuberance of growth under optimum 

 conditions of development. 



432. G-ypsina rubra (d'Orbigny). (PL LIU. figs. 35-37.) 



Planorbulina rubra d'Orbigny, 1826, TMC. p. 280. no. 4. 



„ Foi-nasini, 1908, SON. p. 44, pi. ii. fig. 3. 



3 Stations. 



D'Orbigny recorded this as a nomen nudum from specimens from the South Seas and 

 Sarawak. We have examined his type-specimens in Paris, and they accord in ail 

 respects with the Kerimba specimens. Fornasini, working only on Bertheliu's 

 outline, thought that d'Orbigny 's form was probably identical with Planorhulina 

 mediterranensis d'Orb., but, of course, was not aware of the distinctive coloration and 

 the strong secondary growth exhibited by the actual specimens. 



At Stns. 9, 10, and 11 a few specimens exhibiting a very marked characteristic red 

 coloration. At the latter Stn., where the best specimens were observed, youno- 

 individuals were found resembling a coarsely perforate and somewhat irregular 

 Truncatulina lobatula. This early stage is followed by a growth of chambers which 

 may be either flattened and spreading, or solid and self-investing. In all cases the 

 colour is throughout of a pale rose-pink, lightest in the last-formed chambers. The 

 surface of the chambers is coarsely perforate and often obscured by a deposit of 



