. Bulletin of the Museum of Comparative Zoology at Harvard College. Zoology. VI - 1,2 V - 0,1-3 V - 0,1,2 IV - 0,1-3 Iv - 1,2 III - 1,3 11 - 1,2 Figure 7. Fragiscutum rhytium n. gen., n. sp. Two cranidia showing notation (after Tripp, 1957, 1962) of glabellar tubercles. A) Original of Plate 12, figure 15. B) Original of Plate 12, figure 1. Abbreviatons: Oa, la, 2a, positions of occipital, first and second apodemes; ap, anterior pit; pgf, preglabellar furrow. short, blunt spine. Apodeme (Pi. 11, fig. 3; PI. 12, figs. 13, 17) is curved inward and downward, and situated a short distance in trom t
. Bulletin of the Museum of Comparative Zoology at Harvard College. Zoology. VI - 1,2 V - 0,1-3 V - 0,1,2 IV - 0,1-3 Iv - 1,2 III - 1,3 11 - 1,2 Figure 7. Fragiscutum rhytium n. gen., n. sp. Two cranidia showing notation (after Tripp, 1957, 1962) of glabellar tubercles. A) Original of Plate 12, figure 15. B) Original of Plate 12, figure 1. Abbreviatons: Oa, la, 2a, positions of occipital, first and second apodemes; ap, anterior pit; pgf, preglabellar furrow. short, blunt spine. Apodeme (Pi. 11, fig. 3; PI. 12, figs. 13, 17) is curved inward and downward, and situated a short distance in trom the axial furrow. Ventral surface of pleura does not reflect dorsal surface (Fig. 8b); anterior half is convex down- ward, and there is a deep groove which cur\(s outward just inside the narrow doublure; latter widens and extends across the pleura at the tip. The various struc- tures that facilitate articulation between the segments and limit enrollment are shown in Figure 8a (compare PI. 11, figs. 1-3; PI. 12, figs. 13, 14, 17, 20). The down- ward-projecting ring process fits into a ring socket that surrounds the axial process. The anterior flange on the inner part of the pleura fits beneath the narrow posterior. Figure 8. Fragiscutum rhytium n. gen., n. sp. A) Ventral view of part of a segment. Compare Plate 12, figures 13, 14, 17, 20. B) Section tfirougfi inner part of pleura, in exsagittal plane. Solid black is replaced outer portion of exoskeleton. Abbreviations: afl, anterior flange; ap, apo- deme; axp, axial articulating process; axs, axial articulat- ing socket; d, doublure of axial ring; fp, projection at anterior margin of facet; pb, pleural band; pis, pleural spine; pr, posterior recess; rp, ring articulating process; rs, ring articulating socket; s, silicified lining of canal, appearing as a hollow cone (compare PI. 13, fig. 17); vf, vincular furrow. recess so that in dorsal aspect only the pleural bands are visible. Along the pos- terior edge of the outer part of th
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Keywords: ., bookauthorharvarduniversity, bookcentury1900, booksubjectzoology
