Thurammina papillata Brady .• a Stuchj in Variation, 553 



presenting external views almost identical with Haeusler's later 

 figures, and, in the absence of his type specimens, we are figuring 

 some under the varietal name canaliculata. This is for taxonomical 

 reasons only, as we regard the specimens merely as abnormal 

 growths. 



Summary of Observations. 



All hitherto recorded species of the genus Thurammina, in- 

 cluding Thuramminopsis canaliculata Haeusler, are referable to a 

 single specific type, Thurammina papillata Brady. 



For taxonomical reasons numerous varietal names must be 

 employed, but they have no biological significance. 



Thurammina commences its existence with a chitinous wall, 

 which is persistent through life, and when an agglutinated shell is 

 formed continues as a lining to the shell. 



The wall, whether chitinous or adventitous, is perforate. The 

 perforations may be of the most minute size, or they may take the 

 form of coarse external papilla3. 



Among the " Goldseeker " specimens are several which present 

 great biological interest, and raise questions of relationship and 

 development to which there is no present answer. 



We figure them for purposes of future reference. 



1. Orhulina within T. papillata of a thin-walled sphere type 

 (PL XXIX, fig. 18.). The Orhulina is a thick-walled benthic speci- 

 men, the Thurammina of a semi-chitinous type without visible 

 papillae or constituent sand-grains. Although the Thurammina 

 is, no doubt, more or less flexible, it is difficult to imagine how the 

 Orhulina, which fits tightly inside the sphere, could have become 

 accidentally associated with the Thurammina through the small 

 fractured opening to be observed. If there is no connexion be- 

 tween the life-history of the two genera — and we have at present 

 no other evidence in support of such a theory — the only explana- 

 tion possible seems to be the continued development in size of the 

 Orhulina after becoming interned as a young individual in the 

 cavity of a broken Thuraminina. 



2. A chitinous T. papillata var. castanea inside Orhulina (PI. 

 XXIX, fig. 20). We prefer to regard the association as accidental, 

 althcjugh the accuracy with which the Thurammina fills the entire 

 cavity of the hemisphere, and the chances against such an accidental 

 association, appear remarkable. On any other supposition this 

 specimen must be regarded as the converse of the previously 

 noted abnormality, and would entail belief in an Alternation of 

 Generations between Orhulina and Thurammina. 



3. A chitinous T. papillata of a coarsely papillate type (near var. 

 castanea), enclosed in and nearly filling the cavity of a sub-chitinous 

 individual of a smooth thin-walled sphere type, devoid of papillse 



Dec. 19 th, 1917 2 p 



