98 THE FOEAMINIFEEA 



This elegant little species was first described as a 

 fossil from the Miocene of the Banat. It is a well- 

 known form in the coral sands of tropical areas ; for 

 example, it is common at Funafuti, in the Pacific, 

 at depths ranging from 35 to 150 fathoms, whilst 

 at less depths it seems to be rare. Miocene and 

 Beceiit. (Plate 3, fig. I.) 



Genus Planisjnriiia, Seguenza. 



Chambers equitant, otherwise arranged as in 

 Hauerina ; the lateral alar prolongations of the latest 

 convolution enclosing the previous whorl. Tertiary 

 to Becent. 



Example. — P. contraria, D'Orbigny sp." {BUoculhia 

 Gontraria)^ ' Foram. Fossiles de Yienne,' 1846, p. 266, 

 pi. xvi. figs. 4-6. 



In the earlier part of the shell there are two 

 chambers in each whorl, which increase later to five 

 or six. The walls of the chambers extend over the 

 lateral faces of the shell, as in the nummulite. For this 

 reason Steinmann proposed the name NummolociUina 

 for the genus, which, however, does not stand, since 

 Seguenza's name is of earlier date. The range of 

 this species is from the Miocene to Becent. (Plate 3, 

 fig. J.) 



8uh-familij 4. Peneeoplidin.e. 



The test in this group is planospiral, or cyclical, 

 sometimes crozier-shaped, and bilaterally symme- 

 trical. 



