Foraminifera of South Cormvall. 37 



44. 0. seUeyensis Heron-Allen & Earland. (Eefs., H-A. & E. 1915, F.K.A. 



p. 592.) I, f. ; II, IX, r. ; III, c. ; IV6, VIII6, v.r. 



45. C. involvens (Keuss). (Refs., H-A. & E. 1908, etc. ; S.B. 1909, p. 318 ; 



and 1915, F.K.A. p. 593.) Generally distributed, but never common. 

 (M.) (P.) 



Family ASTEORHIZID^. 



46. Iridia dkiphana Heron-Allen & Earland. (H-A. & E. 1914, F.K.A. 

 p. 371 ; and 1915, p. 608.) Occurs at Station I, young individuals 

 only in tlje hemispherical attached condition, and at Station V 

 , fully grown forms were found. 



Iridia diapliana H-A. & E. 



The synonomy of this species, which is apparently of world-wide 

 distribution, and represents one of the simplest and most primi- 

 tive forms of Arenaceous Foraminifera, is rapidly growing, and, 

 under the International Eules of Zoological Nomenclature,* 

 becomes with each newly-discovered record more complicated. 

 Owing to the wide variability of the test, and the differing degrees 

 of importance assigned by earlier authors to certain features in the 

 construction of the shell,t it appears, in one or other of its life- 

 stages, to have been described under more than one name. 



We have already dealt with the matter at some length else- 

 where,! in connexion with an abnormal form growing between 

 sand-grains, and described by Ehumbler in 1905 as Vanhoefenella 

 f/aussi,^ and which we figured in our Kerimba Monograph ; || but as 

 regards the British specimens, the present appears to be a favour- 

 able opportunity for reviewing the situation. 



In order to deal with the matter fully, we must go back to 

 1854, when Schultze instituted the genus Sqtiamulina,^ which is 

 thus described : — " Shell resembling a flat plano-convex lens with 

 the plane side firmly attached, calcareous, enclosing a simple un- 

 divided space. A large aperture on the convex side ; no fine 

 perforations." He includes the genus, with the genera Gromia and 



* See Report of the IX" Congres International de Zoologie, Monaco, Mars, 

 1913. 



t For the tests of this organism one is tempted to make use of the German 

 equivalent " house " (Gehduse). 



t H-A. & E. 1915, F.K.A. pt. 2, p. 608. 



§ H-A. & E., in Proc. Zool. Soc. (Lond.) 1915, p. 296. Rhumbler's original de- 

 scription was published in Verh. d. Deutsch. Zool. Ges. 1905, p. 105, fig. 9, and he 

 gives a further description and figures in his " Foraminiferen des Plankton Ex- 

 pedition der Humboldt Stiftung," iii. L.C., Kiel and Leipzig, pt. 1, 1909, p. 216, 

 text-fig. 57. 



II H-A. & E., 1914, F.K.A. pi. xxxvi. fig. 10. 



t S. 1854, O.P. p. 56, pi. vi. figs. 16, 17. 



