Thurammina papillata Brady: a Study in Variation. 531 



for he identifies his species T. papillata with the "Orbuline Lituola" 

 figured by W. B. Carpenter in " The Microscope " [5th ed. 1875] 

 (Ref. 1). 



Brady did not make any attempt in the paper of 1879 to deal 

 with the affinities of Thurammina, but in a later paper of the same 

 series published in 1881 (Ref. 3), in which he adumbrated the 

 classification of the Order which was to be adopted in the " Chal- 

 lenger" Monograph, he assigned the genus to the family Lituolidse. 

 The generic definition of Thurammina as published in 1879 is 

 short, but, with a few modifications, sufficient for our present more 

 extensive knowledge of the genus : — 



" Thurammina (Ovpk : a cell ; a/x/xoi; : sand). Test free or 

 adherent, either consisting of a single rounded chamber, sometimes 

 enveloping a similar one -of smaller size, or of two or more 

 (apparently) independent chambers adhering to each other. Tex- 

 ture thin, arenaceous or chitino-arenaceous. Surface beset with 

 numerous perforate nipple-shaped protuberances." 



Brady is less happy in his specific description, having ap- 

 parently failed (perhaps owing to paucity of material) to realize 

 the essentiallv unstable character of the organism. 



A more prolonged study of the subject, aided by a more liberal 

 supply of specimens, would probably have resulted in the suppres- 

 sion of the two species, T. albicans and compressa, or at any rate 

 in their reduction to varietal rank, for he admits their close 

 relationship to the type species Thurammina papillata. 



Butschli in 1880 (in Bronn's " Klassen und Ordnungen des 

 Thierreiches ") (Ref. 4) reproduces two of Brady's (1879) figures of 

 T. papillata (Ref. 2, pi. v, figs. 4 and 6), but ranks the genus 

 with PsammospJuvra, Storthosphmra and Sorosphaera in a supple- 

 ment to his sub-family Globigerinse. 



Carpenter, in the 6th ed. of " The Microscope," published in 

 1881 (Ref. 5), reproduces the same figures as in 1875, but assigns 

 them to Thurammina papillata, "a remarkable imitation of the 

 Orbuline type," and refers to the neatness with which the com- 

 ponent sand-grains of small and uniform size are cemented together 

 so as to present a smooth surface both inside and out. His know- 

 ledge of the genus was apparently confined to the globular type 

 with prominent nipple-shaped protuberances bearing orifices. In 

 the 8th ed. (1901) (Ref. 31) the " Orbuline Lituola " of 1875 has 

 been assigned to Brady's species T. papillata. 



XJhlig, in 1882 (Ref. 6), refers to Brady's recently described 

 genus Thurammina, and records that he had observed in the 

 previous year shells of similar construction in his washings of 

 material from the Jurassic of Brunn. He promises a further 

 study of these forms, which does not appear to have been published 

 in any of his articles which are known to us, or to have- been 

 referred to by other authors. 



