224 



BULLETIN 



UNITED STATES NATIONAL MUSEUM. 



Jaekel here again fails to diagnose his genus, but some of the 

 characters can be clearly made out from his excellent drawing. 

 The disk is small and tends to have convex interbrachial areas. So 

 far as the oral disk area is concerned, the general structure is that 

 of EopJiiura, with this marked difference — the opposite and asterid- 

 like ambulacralia of the rays do not vanish proximally as in that 



genus but crowd over and finally 

 rest wholly upon the adambulacrals, 

 and end against the distal edges of 

 the syngnaths. These are made up 

 ffd/rf )^^ ^v^^^ ®^ ^^® coossified terminal adambu- 



lacral ossicles. 



Genus PROTASTER Forbes. 

 Text fig. 23. 



Protaster Forbes, Mem. Geol. Surv. 

 United Kingdom, dec. 1, 1849, pi. 

 4, pp. 1-2; in McCoy, British Pal. 

 Foss., 1851, p. 60. — ^MuRCHisoN, 

 Siluria, 1854, p. 221, fig. 39-4.— 

 Salter, Rep. Twenty -sixth Meet., 

 Brit. Assoc. Adv. Sci., Notices and 

 abstracts, 1857, p. 76; Ann. Mag. 

 Nat. Hist., ser. 2, vol. 20, 1857, pp. 

 325, 330.— Hall, Nat. Hist. N. Y., 

 Pal., vol. 3, 1859, p. 134.— Salter, 

 Ann. Mag. Nat. Hist., ser. 3, vol. 8, 



1861, p. 484.— Wright, Mon. Brit- 

 ish Foss. Echinod., Oolitic, vol. 2, 

 pt. 1 (Palseontogr. Soc. for 1861), 



1862, pp. 23, 31.— Hall, Twentieth 

 Rep. N. Y. State Cab. Nat. Hist., 

 1868, p. 293; rev. ed., 1868=1870, 

 p. 335.^ — QuENSTEDT, Petrefacten- 

 kunde Deutschlands, vol. 4, 1876, 

 p. 133, pi. 95, fig. 11.— STiJRTz, N. 

 Jahrb. fiirMin., etc., 1886, vol. 2, 

 pp. 148, 150. — Gregory, Geol. 

 Mag., dec. 3, vol. 6, 1889, p. 26.— 

 Stx)rtz, Verh. naturh. Ver. preuss. 

 Rheinl., etc., vol. 50, 1893, p. 18.— 

 J. F. James, Journ. Cincinnati Soc. 



Nat. Hist., vol. 18, 1896, p. 137.— Gregory, Proc. Zool. Soc. London for 1896, 

 1897, p. 1031, fig. 1.— WmDBORNE, Palseontogr. Soc, 1898, p. 206.— Parks, 

 Trans. Canadian Inst., vol. 8, 1908, pp. 363, 366.— Schondorp, Jalirb. nas- 

 sauisch. Ver. Naturk., Wiesbaden, vol. 63, 1910, p. 238.— Sollas and Sollas, 

 Philos. Trans. Roy. Soc. London, ser. B, vol. 202, 1912, p. 223.— Spencer, 

 Mon. Brit. Pal. Asterozoa, pt. 1 (Palseontogr. Soc. for 19J3), 1914, p. 35. 



Encrinastcr (part) Haeckel, Gen. Morphologic, vol. 2, 1866, p. Ixvii (no definition). 



Alec see Stiirtzura. 



FiG.21.— Ventral VIEW of a ray of Bohemura 



JAHNI, ENLARGED ABOUT X 2, AFTER JaEKEL. 



a, ambulacralia; ad, adambulacralia with 



THEIR LATERAL EXTENSIONS; adm, SYNGNATHS. 



