Using laboratory cultured larvae of P. hirsutiusculus from Puget Sound, Washington, the durations of the four zoeal stages and the external anatomy and dissected appendages of the five larval stages are described and drawn. The species is placed within Group A of the established groupings of Pagurus larvae. Comparisons with a California study of the species show variation in stage duration and body length, but minor differences in anatomy and appendages. A compilation of total larval body lengths from 19 Pagurus species is presented. Photoperiod during larval development does not appear to be significant in regulating growth and survival of P. hirsutiusculus.