ABSTRACT: In a recent article, Munguia et al. (2010; Mar Ecol Prog Ser 413:229–240) presented a spatially explicit mathematical model of competition among 4 sessile species of benthic invertebrates. We argue that, based on the description of the model, it is impossible to repeat the analysis without making numerous guesses and assumptions. Furthermore, the results do not correspond to the model as it is described. We highlight elements of the model formulation and description relating to dispersal, colonization, and competition that, if clarified, would help the reader to understand, evaluate, and extend the results of this study.