. Bulletin - United States National Museum. Science. KEVISION OF PALEOZOIC STELLEEOIDEA. 255 buliicriil ossicles. In Ilallaster the lateral wiiigs of the plates curve round the podial openings proximally, while in Lapwortliura thc}^ do SO distally. Further, the side plates of the latter genus bear spines along their sides, while in the former genus they are restricted to the distal ends of the plates. HALLASTER FORBESI (HaU). Text fig. 31. Protaster forbesi Hall, Nat. Hist. N. Y., Pal., vol. 3, 1861, p. 134, pi. 7A, figs. 8-10; Twentieth Rep. N. Y. State Cab. Nat. Hist., 1868, p. 293, pi. 9, f
. Bulletin - United States National Museum. Science. KEVISION OF PALEOZOIC STELLEEOIDEA. 255 buliicriil ossicles. In Ilallaster the lateral wiiigs of the plates curve round the podial openings proximally, while in Lapwortliura thc}^ do SO distally. Further, the side plates of the latter genus bear spines along their sides, while in the former genus they are restricted to the distal ends of the plates. HALLASTER FORBESI (HaU). Text fig. 31. Protaster forbesi Hall, Nat. Hist. N. Y., Pal., vol. 3, 1861, p. 134, pi. 7A, figs. 8-10; Twentieth Rep. N. Y. State Cab. Nat. Hist., 1868, p. 293, pi. 9, figs. 5, 6; rev. ed., 1868=1870, p. 336, pi. 9, figs. 5, 6.âQuenstedt, Petrefacten- kunde Deutschlands, vol. 4, 1876, p. 134, pi. 95, fig. 13.âSturtz, Palaeonto- graphica, vol. 32,1886, pp. 78, 83. Hallastcrforbesi Sturtz, N. Jahrb. fiir Miu., etc., 1880, vol. 2, p. 150. The original description will not be repeated here because it is faulty and was later corrected by Hall. HaJVs description of 1S68.â "has a circu- lar disk, composed of squamiform spmiferous plates and five long flexuous rays. These rays I have [originally] represented as composed, on the lower side, of a double range of [adambulacral] plates, as described and represented by Professor Forbes, ])ut ^^°- 3i.âacttnal ray n ^⢠J ⢠1 i- J1 p n ⢠i PLATES OF HaLLASTER nndmg outside oi these a range oi small ossicles forbesi (Hall). op- [side plates] to which are attached the spme bases, '''^^"^ ambul^crals, ,â¢â 1 IT ,/. ,⢠1 ⢠-^^'^ THE SIDE PLATES. these nave been shown as a part oi an articulatmg spine (in the illustration, plate 7^^), an unnatural representation, which I am now able to correct. " In the species from the Lower Helderberg group, Protaster jorbesi, the ventral surfaces of the rays are composed of an ambulacral and adambulacral series of plates on each side [there are no ventral ray plates]. The ambulacral plates are obliquely quadrangular and alter- na
Size: 1743px × 1434px
Photo credit: © Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorun, bookcentury1800, bookdecade1870, booksubjectscience
