A Study of Absorption Features in the Three Micron Spectra of Molecular Cloud Sources with H${}_2$O Ice Bands

New 3.3–3.6~$\mu$m spectra were obtained of nine young stellar objects embedded in molecular clouds. An absorption feature at $\sim$3.47~$\mu$m (2880~cm${}^{-1}$) with FWHM$\sim$0.09 $\mu$m (80 cm${}^{-1}$), first identified by Allamandola et al. (1992), was definitively detected toward seven objects, and marginally in the other two. The feature is better correlated with H${}_2$O ice than with the silicate dust optical depth in the data obtained to date. Assuming the feature is due to a C–H stretch absorption, the abundance of the C–H bonds averaged along the lines of sight is closely related to that of H${}_2$O ice. We interpret the correlation with H${}_2$O ice as indicating that the C–H bonds form together with H${}_2$O ice on grain surfaces in the molecular clouds, though other formation mechanisms are not ruled out. A second absorption feature at 3.25 $\mu$m (3080 cm${}^{-1}$) was detected toward NGC7538/IRS 1 and S140/IRS 1; this feature was first detected in spectra of MonR2/IRS 3 (Sellgren, Smith, & Brooke 1994; Sellgren et al. 1995). There is as yet insufficient data to tell whether this feature is better correlated with H${}_2$O ice or silicates.