In their 2012 paper discussing the character of pores and organic matter in the Mississippian Barnett Shale, Bernard et al. (2012) identified only nonporous kerogen and nonporous solid bitumen in oil-window-maturity samples, but nanoporous pyrobitumen in gas-window-maturity samples. Our examination of samples from the same wells shows that pores are also present in organic matter from oil-window-maturity samples. We also argue that some of the pores we identified in gas-window-maturity samples are developed in organic matter that is unlikely to be pyrobitumen. (C) 2013 Elsevier B.V. All rights reserved.