Clark, A. H. (1907). A new species of crinoid (Ptilocrinus pinnatus) from the Pacific Coast, with a note on Bathycrinus. <em>Proceedings of the U.S. National Museum.</em> 32:551–554.[details]
original descriptionClark, A. H. (1907). A new species of crinoid (Ptilocrinus pinnatus) from the Pacific Coast, with a note on Bathycrinus. <em>Proceedings of the U.S. National Museum.</em> 32:551–554.[details]
Other
additional sourceRoux M, Lambert P (2011) Two new species of stalked crinoids from the northeastern Pacific in the genera <i>Gephyrocrinus</i> and <i>Ptilocrinus</i> (Echinodermata, Crinoidea, Hyocrinidae). Effects of ontogeny and variability on hyocrinid taxonomy. <i>Zootaxa</i> 2825:1–54.[details]