Sheffield and Sumrall—Generic revision of North American Holocystitidae
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Figure 6. (1) Holocystites scutellatus (SUI 48183) oral view. (2) Interpretation of oral area of Holocystites scutellatus; note that facet-bearing facetal plates are loosely positioned on more than one facetal. (3) Pentacystis gibsoni (SUI 46316) oral view. (4) Interpretation of oral area of Pentacystis gibsoni; note five facetal scars lying atop facet-bearing plates and semiprotuberant summit. Attachment scars on the oral area of Pentacystis (SUI 46316) clearly show where O1–O6 were attached before they were disarticulated. (5) Osgoodicystis bissetti Frest and Strimple, 2011 in Frest et al., 2011 (SUI 48166) oral view. (6) Interpretation of oral area of Osgoodicystis bissetti shows a plating pattern identical to that of Pentacystis, with the exception that the oral plates are still intact. (7) Trematocystis magniporatus (SUI 48198) oral view. (8) Interpretation of oral area of Trematocystis; note absence of A ambulacrum and firm positioning of facets on one facetal plate. (9) Paulicystis sparsus (48164) oral view. (10) Interpretation of oral area of Paulicystis sparsus; note absence of A ambulacrum and presence of recumbent ambulacral scars on the theca. OO indicates disarticulated oral plates of this specimen. Open circles on O7 indicate position of gonopore. O = oral plate; P = periproct; M = mouth. Scale bars = 1 cm. Modified from Sheffield and Sumrall (2015a).
