MRS continuum-subtracted spectra of C₂H₂ (magenta), HCN (green), H₂O (blue), and CO₂ (brown) emission lines between 13.6 and 15.3 μm from JDISCS sources with submillimeter dust sizes r > 63 au. ALMA images are shown to the right of the spectra (S. M. Andrews et al. 2018; F. Long et al. 2018, 2019; F. Long et al. 2025, in preparation), in order of submillimeter dust disk size from largest (top left; Elias 27, r ∼ 250 au) to smallest (bottom right; RU Lup, r ∼ 63 au). Slab model fits to the molecular emission lines are overplotted on the spectra, corresponding to the best-fit parameters and upper limits reported in Tables 5, 6, 7, and A1. ¹³C¹²CH₂ emission is also detected in the spectrum of GO Tau, along with multiple CO₂ isotopologues in MY Lup (C. Salyk et al. 2025), and an OH-rich spectrum with no CO₂ emission from GM Aur (C. E. Romero-Mirza et al. 2025, in preparation).