From a 1000 cm 3 sample containing nearly 13,500 fusulinids of the species Triticites ventricosus [Permian, Wolfcampian, Wabaunsee County, Kans.], number of chambers (X) of 5166 individuals was estimated from length in millimeters (Y) using the regression equation Y = 0.114 + 0.369X. A composite life table and survivorship curve indicate lowest mortality rate among individuals with 60 to 69 chambers. Juvenile mortality rate is much lower than that of some other marine organisms, suggesting that early growth may have taken place in a reproductive cyst.