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The discovery over the last several decades of moderate luminosity AGNs indisk-dominated galaxies - which show no "classical" bulges - suggests thatsecular mechanisms represent an important growth pathway for supermassive blackholes in these systems. We present new follow-up NuSTAR observations of theoptically-elusive AGNs in two bulgeless galaxies, NGC 4178 and J0851+3926. NGC4178 was originally reported as hosting an AGN based on the detection of [Ne V]mid-infrared emission detected by Spitzer, and based on Chandra X-ray imagingit has since been argued to host either a heavily obscured AGN or a supernovaremnant. J0851+3926 was originally identified as an AGN based on its WISEmid-IR colors, and follow-up near-infrared spectroscopy previously revealed ahidden broad line region, offering compelling evidence for an optically-elusiveAGN. Neither AGN is detected within the new NuSTAR imaging, and we derive upperlimits on the hard X-ray 10-24 keV fluxes of $<7.41\times10^{-14}$ ergcm$^{-2}$ s$^{-1}$ and $<9.40\times10^{-14}$ erg cm$^{-2}$ s$^{-1}$ for theAGNs in NGC 4178 and J0851+3926, respectively. If these non-detections are dueto large absorbing columns along the line of sight, the non-detections in NGC4178 and J0851+3926 could be explained with column densities oflog($N_{\rm{H}}/\rm{cm}^2)>24.2$ and log($N_{\rm{H}}/\rm{cm}^2)>24.1$,respectively. The nature of the nuclear activity in NGC 4178 remainsinconclusive; it is plausible that the [Ne V] traces a period of higheractivity in the past, but that the AGN is relatively quiescent now. Thenon-detection in J0851+3926 and multiwavelength properties are consistent withthe AGN being heavily obscured.

NuSTAR Observes Two Bulgeless Galaxies: No Hard X-ray AGN Detected in NGC 4178 or J0851+3926