THE FAMILY NUMMULINID^ 235 



Some species of Fusulina attain a length of half 

 an inch. They constitute a large proportion of the 

 Upper Carboniferous limestones of certain localities, 

 as in Kussia, the Arctic Eegions, Armenia, India, 

 China, Japan, the United States (Iowa, Illinois, 

 Kansas, Utah, New Mexico, and California), and 

 British Columbia. In Central Europe also the 

 Zechstein (of Permian age) contains Fusulina. 

 (Plate 13, figs. A, a.) 



The sub-genera Hemifusulina and Fusuliiiella of 

 Moller are modifications of the typical Fusulina, and 

 they are confined to the Carboniferous formation. 

 Hemi fusulina resembles Fusulina in form and 

 general structure, but with the exception that it 

 possesses a double septal wall. Fusulinelht may be 

 compared with a Fusulina which has been compressed 

 on the axis of the umbilicus, the resulting form being 

 a complanate nautiloid shell, like Nonionina. The 

 brown bituminous Carboniferous limestone of Kussia 

 and China contains Fusulina, FusulineUa, and Hcliwa- 

 gerina. The specimens of the latter genus are often 

 found infilled with the hydrocarbonaceous material 

 of the rock-matrix. 



Genus ScJiwagerina, Mollee, 



Test subglobular, elongated, or subcylindrical, 

 seldom fusiform ; chambers subdivided by true 

 secondary septa ; aperture either a simple central 

 fissure or a row of rounded pores. Carhoniferous. 



Example. — H. j^i^incej^s, Ehrenberg sp. (Boi^elis), 

 ' Mikrogeologie,' 1854, pi. xxxvii. figs. x. c, 1-4 ; 



