Br. J. W. Gregory — On Palceozoic Starfishes. 349 



1. PALiEASTERINA, McCoy, 1851. 

 Synonymy.^ 

 Faheasteriiia, McCoy, 1851 : Brit. Palaeoz. Foss., fasc. i, p. 59. 



,, pars, Salter, 1857, "New Pal. Starfishes" : Ann. Mag. Nat. Hist., 



ser. 2, vol. xx, pp. 324, 327. 

 ,, pars, Billings, 1858 : Dec. Geol. Surv. Canada, No. iii, p. 76. 



,, pars, Salter, 1859: in Murchison, " Silui-ia," 3rd ed., p. 248. 



iioH ,, Dana, 1863, "Note foss. Echinod." : Amer. Journ. Sci., ser. 2, 



vol. XXXV, p. 295. 

 non ,, Hicks, 1873, " Tremadoc St. Dav.'' : Quart. Journ. Geol. Soc, 



vol. xxix, p. 51, pi. iv, figs. 21-23. 

 non „ Baily, 1879 : Mem. Geol. Surv. Ireland, No. 169, etc., p. 58. 



,, von Zittel, 1879 : Handb. Palaeont., vol. i, p. 453. 



non ,, Etheridge, 1881 : Pres. Add., Quart. Journ. Geol. Soc, vol. xxxvii, 



Proc, p. 92. 

 ,, pars, De la Touche, 1884 : Handb. Geol. Strops., p. 34. 



non ,, Stiirtz, 1886, " Beitr. pal. Seest." : Palseontogr., vol. xxxii, p. 96. 



„ Stiirtz, 1890, " Neu. Beitr. pal. Seest." : ibid., vol. x.'sxvi. p. 226. 



,, pars, Stiirtz, 1893, " Ueber verst. und leb. Seest."; Yerh. naturh. 



Ver. preuss. Rheinl., ser. 5, vol. x, p. 43. 

 Uraster, pars, Forbes, 1848, "Aster, foss. Brit." : Mem. Geol. Surv., p. 463. 

 ,, ,, Forbes, 1849 : Dec. Geol. Surv., No. i, pi. i. 



Diagnosis. 



Palseasteriiiidfe with the rays shortly produced but distinctly 

 marked off from the disc. B is about twice as great as r. 



The skeletal plates are large and thick, but not packed into 

 a tessellate pavement, the separate plates on the disc being 

 rounded and isolated. There is a circle of five pairs of plates 

 round the centre of the abactinal side ; from this circle series 

 of four longitudinal rows of plates pass outward down each ray. 

 The plates of the longitudinal series become crowded and 

 subpol^'gonal at the distal end of the rays. 



On the actinal side the interbrachial areas are covered with 

 isolated, rounded, or subangular plates, bearing spines. The 

 marginal plates are small and usually bear small spines. 

 The presence of supramai'ginals is doubtful. 



The adambulacral ossicles are boot-shaped, and the ambulacral 

 groove is bordered by a series of large adambulacrals. 



Type Species. — Palcenslerina primceva (Forbes), 1848.- Mem. 

 Geol. Surv., vol. ii, pt. 2, p. 463 ; 1849, Dec. Geol. Surv., dec. i, 

 pi. i, fig. 2. Ludlow Series : Underbarrow, Westmoreland. 



PALiEASTERINA BoNNEYI, n.Sp. PI, XVI, PJgS. 2a, 6. 



Diagnosis. 



Eays short and blunt, tapering regularly ; disc rounded or sub- 

 pentagonal. The ratio of R to r is 2 : 1. 



On the abactinal surface there are three longitudinal series of large 

 plates, crowded distally, but separated by areas bearing smaller 

 plates in the disc. 



1 The references included in the above list show some of the limitations to which 

 the genus must submit. 



2 Salter and J. de C. Sowerby in 1843 recorded an asterid from the Arenig beds as 

 Asterias primceva, but apparently it was never described (Quart. Journ. Geol. Soc, 

 vol. 1, p. 8, and table i, opposite p. 21). 



