We consider the effect of optical depth of the 2 ~ { } ^ { 3 } S~ { } level on the nebular recombination spectrum of He I for a spherically symmetric nebula with no systematic velocity gradients .
These calculations , using many improvements in atomic data , can be used in place of the earlier calculations of Robbins .
We give representative Case B line fluxes for UV , optical , and IR emission lines over a range of physical conditions : T = 5000 - 20000 K , n _ { e } = 1 - 10 ^ { 8 } ~ { } { cm ^ { -3 } ~ { } } , and \tau _ { 3889 } = 0 - 100 .
A FORTRAN program for calculating emissivities for all lines arising from quantum levels with n \leq 10 is also available from the authors .

We present a special set of fitting formulae for the physical conditions relevant to low metallicity extragalactic H II regions : T = 12 , 000 - 20 , 000 K , n _ { e } = 1 - 300 ~ { } { cm ^ { -3 } ~ { } } , and \tau _ { 3889 } < 2.0 ) .
For this range of physical conditions , the Case B line fluxes of the bright optical lines 4471 Å , 5876 Å , and 6678 Å , are changed less than 1 % , in agreement with previous studies .
However , the 7065 Å corrections are much smaller than those calculated by Izotov & Thuan based on the earlier calculations by Robbins .
This means that the 7065 Å line is a better density diagnostic than previously thought .
Two corrections to the fitting functions calculated in our previous work are also given .