Clark, A. H. (1907). A new species of crinoid (Ptilocrinus pinnatus) from the Pacific Coast, with a note on Bathycrinus. Proceedings of the U.S. National Museum. 32:551–554.
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Clark, A. H.
1907
A new species of crinoid (Ptilocrinus pinnatus) from the Pacific Coast, with a note on Bathycrinus