. Bulletins of American paleontology. North American Paracrinoidea: Parsley & Mintz 65 The periproct is generally small and was covered by an anal pyramid of eight or nine wedge-shaped plates. The hydropore-gonopore combination is typical among para- crinoids. The margins of the hydropore are elevated more than in other genera. Other thecal openings under the recumbent arms will be discussed below. Arms. — The arms, like those of Amygdalocystiles, are trans- versely arranged (PI. 8, fig. 1). In the case of P. cristatus, when the peristome is oriented uppermost, the ends of the arms do not
. Bulletins of American paleontology. North American Paracrinoidea: Parsley & Mintz 65 The periproct is generally small and was covered by an anal pyramid of eight or nine wedge-shaped plates. The hydropore-gonopore combination is typical among para- crinoids. The margins of the hydropore are elevated more than in other genera. Other thecal openings under the recumbent arms will be discussed below. Arms. — The arms, like those of Amygdalocystiles, are trans- versely arranged (PI. 8, fig. 1). In the case of P. cristatus, when the peristome is oriented uppermost, the ends of the arms do not extend past a horizontal plane placed at the point where the right arm reaches a vertical position on the theca. Rarely does the right arm pass the vertical when the theca is so oriented that the food groove is overturned and its longitudinal axis is pointed away from the peristome. The left arm, in some instances, extends to the column attachment, and in rare instances extends down the column, as evidenced by arms broken at the column attachment. The extent to which the arm extends down the left side is an intra-species vari-. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Paleontological Research Institution (Ithaca, N. Y. ); Columbia University. Ithaca, N. Y. , Paleontological Research Institution [etc. ]
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