166 Proceedings of the Royal Irish Academy. 



plan, and quite recently, in preparing our monograph of the Foraminifera 

 biought home by the "Terra Nova" Expedition of 1910, we have found in 

 dredgings from Xew Zealand specimens of these free forms, some at the 

 actual moment of developing their earliest " adherent " chambers, and a series 

 progressing to the most fully developed arborescent forms. 



Similar specimens from an nnrecoided locality are to be found in the 

 W. B. Carpenter collection in the Museum at Exeter. It should be pointed 

 out that the number of specimens of this early and free form observed is out 

 of all proportion to what might be expected if it were a normal method of 

 development. 



(? vii) It would be perhaps premature to establish a variation of habit 

 upon what is at present, in our experience, a solitary instance ; but it will 

 not be out of place to refer to the remarkable specimens of Cymhalopoia 

 taMlaeformis, Brady, recorded by us from the Kerimba Archipelago,'* and 

 suljsequently discussed at length by Heron-Allen." These oi-ganisms had 

 " encryptetl " themselves in pits in the surface of molluscan fragments, 

 enlarging their cr>pts as they grew to maturity by a process which is at 

 present unknown. The instance was unique in our experience, and has not, 

 so far as we are aware, been recorded by any student of the Foraminifei-a. 



It is, however, time to address ourselves to the description of our 

 experiments and observations upon Vtmeuilina jtolt/siro/Jta (iJeuss). We 

 were led into the inquir}', the results of which are now recorded, by two 

 groups of circumstances, arising out of experiments carried out in our tanks 

 at Selsey, the earlier results of which have been recorded by us elsewliere. 



The first was an experimental culture of the robust and common Miliolid, 

 MasfiJina sfcam (d'Orb.) in sea-water unintentionally rendered hypertonic 

 by the continual addition of well-water of marked hardness (owing to the 

 presence of line), to make up for evaporation from the surface of the tank. 

 The results of this experiment were first recorded in 1910.'* Not only was 

 a remarkable series of wild-growing monsters produced, but a large number 

 of the specimens came to maturity showing all the distinctive features 

 of three previously established " varieties," to wit, jVassiJiiia dentindata, 

 Costa, M. obiigvesiTuita, IJalkyard. and .\f. ftiiuisiriata, Earland." It afforded 

 an excellent object-lesson and warning as to the multiplication of specific 



* E. Heron-Allen and A. Euimnd : "The Fonminifera of the Kerimba Archipelago." 

 Tnms. Zool. Soc. (Loudon), vol. xx. 1915. p. 688. 



» Lor. eU. (note 23). p. 258, PI. iviu. figs. 55, 56. 



*> E. Heron- Allen and A. Earland : "The Recent and Fossil Foraminifera of the 

 Shore Sands at Selsey Bill, Sussex." J. R. >licT. Soc., 1908-11 (1910). pp. 693-695. 



♦' These induced variations and monstrosities, and the three resulting species, were 

 fitfured in 1915 by Heron- Alien. Lor. cit. (note 23), p. 262, PI. xviii, figs. 57, 58. 



