nSTUIiOSE POLTMORPHIN^, AJfD GENUS EAMULINA. 499 



In 5 tlie marginal growth, being only at the oral end of the 

 shell, presents, though it is strongly dentate, an analogy to the 

 crest-like apical growth (" damcBcornis ") of 4, and is here 

 grouped with it. 



V. Mixed growths. — A flatly racemose marginal outgrowth is 

 associated with the apical in 67 ; also with the apical (broken) 

 in 68 ; and with both apical and suhapical growths in 69 : 

 therefore it cannot be regarded as a peculiar or special con- 

 dition. 



So also the mixed conditions of apical with subapical, or with 

 scattered patches and tubules, cannot be set apart ; for the 

 racemose-apical falls in with some of the other modifications, as 

 61, 62, 63, 66— see the list of forms. 



The frequent occurrence of apical extrusions, and the proba- 

 bility of the marginal and other superficial exogenous growths 

 having started from the aperture of the apex and stretched 

 downwards (backwards), shows at least that only adult 

 individuals produced them ; and probably the perforations left 

 after excrescences have been removed were due to absorption of 

 the intervening shell-wall (as suggested by T. Alcoek), so as to 

 allow of direct communication of the inner and outer sarcode *. 



"We cannot entertain the notion formerly advanced by 

 M. O. Terquem, that any of these outer growths may be due to 

 parasitical Polyzoa allied to Cellepora f ; for we regard them as 

 a permanent calcareous tubing of the chief pseudopodia. 



In none of the foregoing Fistulose Polymorphince do we find 

 tubes and tubules exactly corresponding with the tubular struc- 

 tures that have been referred to Ramulina. 



A Polymorphine form figured by Beissel, and much like our 

 " diffusa" shows a peculiar structure, such as we find in Bamu- 

 lina%. Hence we think it best to take this internal structure, 



* T. Alcock. — " On Polymorphina tuhulosa." Proc. Lit. Phil. Soc. Man- 

 chester, vol. Ti. 1867, pp. 85-90. 



t O. Teequem. — " Les Foraminiferes du Pliocene superieur de I'lsle de 

 Rhodes." M6m, Soc. Geol. France, ser. 3, vol. i. 1878, no. 3, pp. 1-133. 



\ T. Beissel and E. Holzapfel. — " Die Foraminiferen der Aachener 

 Kreide." Abhandl. Konigl. Preuss. geol. Landesaustalt, neue Folge, Heft 3, 

 1891, p. 59, pi. xii. figs. 9-16. 



41* 



