Thuramviina papillata Brady : a Study in Variation. 533 



beds with abundant Hyper amminx^ {H. vagans Brady). . The same 

 association is noticeable in most of the " Goldseeker " dredgings ; 

 wherever H. vagans and H. ramosa form a considerable percentage 

 of the rhizopodal fauna Thuramminse occur in numbers. The 

 association of the Hyperammince with a sponge fauna is more 

 readily understood, as both species of Hyperammina, and especially 

 H. ramosa, employ sponge spicules largely in the construction and 

 armament of their tubes. 



Haeu.sler states that " in comparing a great number of specimens 

 of different ages and localities we find that the species can be 

 divided into a number of groups, each of which contains some 

 characteristic and often remarkably constant varieties. But owing 

 to their great variability most of them can be connected through 

 intermediate forms, forming thus a single series from the simple 

 sphseroidal to the most complicated types As the distribu- 

 tion of the recent T. papillata is world-wide, its oldest fossil 

 representatives seem to be present in the deep sea sediments all 

 over Europe in countless modifications, many of which have not 

 been found in a recent state. On the other hand, the globular 

 large varieties with small papillae and very finely arenaceous tests 

 of our existing seas are not known in a fossil condition." 



Haeusler records that the tests of all the Jurassic specimens of 

 T. papillata are very thin, composed of small grains of quartz 

 sand, neatly fitted together, and united by a colourless brownish 

 or vellow cement. It would thus appear that his fossils, although 

 presenting an equal or even greater range of external form than 

 recent specimens, were more limited in their range of structure. 

 The chitinous tests, devoid of all arenaceous investment which occur 

 in many " Goldseeker " dredgings, do not appear to be represented 

 in the Jurassic, unless, as seems probable, Haeusler is referring to 

 this type of shell when he describes certain specimens as hyaline, 

 a form of structure unknown in recent Thuram7ninas and incom- 

 patible with all we know of the genus. 



The Jurassic specimens of T. papillata were divided by Haeusler 

 into eleven groups, but without varietal names, and references for 

 each group are given to figures on the plate accompanying the 

 paper. All the groups occur among our " Goldseeker " material. 



The same year, 1883, was marked by tlie publication of 

 Haeusler's paper on the new genus Thuramminopsis (Ref. 11). 

 He had already foreshadowed it by a reference to the single species 

 as Thnrammina canaliculata in the previous year (Ref. 7). 

 Haeusler's type-specimens, if they were ever brought to this 

 country, have apparently disappeared, at any rate enquiries in all 

 likely quarters have proved unfruitful. "We are therefore compelled 

 to fall back upon his published description and figures, supple- 

 mented by the further information contained in his later reference 

 to the same form in 1890 (Ref. 21). No subsequent discovery 



