. The Annals and magazine of natural history; zoology, botany, and geology. Natural history; Zoology; Botany; Geology. the Crinoidea, Cystidea, and Blastoidea. 149 supposes to be both mouth and vent, Avhich accords witli my view (Mon. der Blastoideen, p. 378). In 1868 I discovered the five small pores at the apical extremities of the ambulacral grooves (Sillimati's Amer. Joum. ser. 2. No. 97, p. 353, and Ann. Nat. Hist. ser. 4. vol. iv. p. 76). In general it is diffi- cult to see these pores ; but if a siliciiied specimen, which has been fossilized in a calcareous matrix, be placed in an acid
. The Annals and magazine of natural history; zoology, botany, and geology. Natural history; Zoology; Botany; Geology. the Crinoidea, Cystidea, and Blastoidea. 149 supposes to be both mouth and vent, Avhich accords witli my view (Mon. der Blastoideen, p. 378). In 1868 I discovered the five small pores at the apical extremities of the ambulacral grooves (Sillimati's Amer. Joum. ser. 2. No. 97, p. 353, and Ann. Nat. Hist. ser. 4. vol. iv. p. 76). In general it is diffi- cult to see these pores ; but if a siliciiied specimen, which has been fossilized in a calcareous matrix, be placed in an acid for two or three minutes, the acid cleans them out, and they then become distinctly visible. I believe these to be the pores through which the ovarian tubes passed outward along the grooves to the pinnulse. There are thus sixteen apertures in the apex of Nucleocrinus—ten spiracles, five ovarian orifices, and one oro-anal aperture. There are no true radial plates. The whole of the test, with the exception, perhaps, of the ambulacra, belongs to the perisomatic system. 8. On the occurrence of Embryonic Forms among the Falceozoic Fi-. 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 London, Taylor and Francis, Ltd
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