We examine the Mg II 2796 , 2803 Å , Lyman \alpha , and nebular line emission in five bright star-forming galaxies at 1.66 < z < 1.91 that have been gravitationally lensed by foreground galaxy clusters .
All five galaxies show prominent Mg II emission and absorption in a P Cygni profile .
We find no correlation between the equivalent widths of Mg II and Lyman \alpha emission .
The Mg II emission has a broader range of velocities than do the nebular emission line profiles ; the Mg II emission is redshifted with respect to systemic by 100 to 200 km s ^ { -1 } .
When present , Lyman \alpha is even more redshifted .
The reddest components of Mg II and Lyman \alpha emission have tails to 500–600 km s ^ { -1 } , implying a strong outflow .
The lack of correlation in the Mg II and Lyman \alpha equivalent widths , the differing velocity profiles , and the high ratios of Mg II to nebular line fluxes together suggest that the bulk of Mg II emission does not ultimately arise as nebular line emission , but may instead be reprocessed stellar continuum emission .