CHAPTER ly. 

 PROTOZOANS AND SPONGES. 



Fusulina cylindrica Fischer. 



Plate xii, tigs. la-c. 



Fusulina cylindrica Fischer, 1837: Orcyst. du G-ouv. de Moscau, p. 126, 

 pi. xviii, figs. 1-5. 



Fusulina cylindrica Owen, 1S52 : Geo!. Sur. Iowa, Wisconsin and Minne- 

 sota, p. 130. 



Fusulina cylindrica Meek and Hayden, 1864: Pal. Upper Missouri, p. 14, 

 pi. i, figs. Qa-c. 



Fusulina cylindrica Geinitz, 1866 : Garb, und Dyas in Nebraska, p. 71, tab. 

 V, fig. 5. 



Fusulina cylindrica Mepk, 1872: U S. Geol. Sur. Nebraska, p. 140, pi. i, 

 fig. 2 ; pi. il, fig. 1 ; pi. V, figs. 3a-b ; pi. vii, figs. 8a-b. 



Fusulina cylindrica White, 1877: U S. Geol. Sur. W. 100 Merid., vol. IV, 

 p. 96, pi. vi, figs. Qa-b. 



Fusulina cylindrica Keyes, 1891 : Proc. Acad. Nat. Sci., Phila., p. 245. 



Eather small, seldom exceeding six millimeters in length 

 of axis, fasiform, more or less ventricose medially, and blunt 

 at the ends, which are often slightly twisted. Surface marked 

 by rather distinct septal furrows. Aperture very narrow. 

 Volutions seven to eight, closely coiled. Septa from twenty to 

 thirty or more in number in the last whorl. Foramina quite 

 distinct in well-preserved specimens. 



Horizon and Localities. — Upper Carboniferous, Coal Meas- 

 ures : Kansas City, Lexington. 



This species is very widely distributed both in time and 

 space and as a matter of consequence it presents, as might be 

 expected, many varietal phases. There is, therefore, apparently 

 very good grounds, as suggested by White, for regarding the 

 various forms described as Fusulina depressa^ F. ventricosa, F. 

 robustttf F. gracilis, etc., as identical with F. cylindrica, the 

 slight differences being due to local variations of environment 

 rather than specific modifications ia structure. 



