REVISION OF PALEOZOIC STELLEEOIDEA. 167 



STENASTER (?) OBTUSUS (Forbes), 



Asterias primxva Salter and Soweuby, Quart. Jour. Geol. Soc. London, vol. 



1, 1845, p. 8, 20 (table) (nomen nudum). 

 Uraster obtusus Forbes, Mem. Geol. Surv. Gt. Britain, vol. 2, pt. 2, 1848, p. 463; 



Mem. Geol. Surv. United Kingdom, dec. 1, 1849, p. 2, pi. 1, fig. 3. — Murchi- 



soN, Siluria, 1854, p. 182, fig. 17. 

 Palxaster obtusus Salter, Ann. Mag. Nat. Hist., ser. 2, vol. 20, 1857, p. 320. — 



Wright, Mon. British Foss. Echinod., Oolitic, vol. 2, pt. 1 (Palseontogr. 



Soc. for 1861), 1862, p. 24.— Salter, Mem. Geol. Surv. Gt. Britain, vol. 3, 



1866, p. 289, pi. 23, fig. 1. 

 Stenastcr (?) obtusus Stijrtz, N. Jahrb. fiir Min., etc., 1880, vol. 2, p. 153; Verb. 



naturh. Ver. preuss. Rheinl., etc., vol. 50, 1893, pp. 41, 50. 

 Stenaster obtusus Spencer, Mon. Brit. Pal. Asterozoa, pt. 1 (Palteontogr. Soc. for 



1913), 1914, pp. 22, 23, 31, text fig. 21, pi. 1, figs. C, 7. 



The little that is known of this species appears to be in harmony 

 with the characters of Stenaster as here defined. It occurs in the 

 Caradoc beds (Ordovicic) at Drumcannon, Waterford, Ireland, and 

 in the Bala rocks west of Bala Lake (Moel-y-Garnedd), North Wales. 



STENASTER (?) CORONELLA (Salter). 



Palxaster coronella Salter, Ann. Mag. Nat. Hist., ser. 2, vol. 20, 1857, p. 320.—. 



Wright, Mon. British Foss. Echinod., Oolitic, vol. 2, pt. 1 (Pala^ontogr. 



Soc. for 1861), 1862, p. 25. 

 Stenaster (?) coronella Sturtz, N. Jahrb. fiir Min., etc., 1880, vol. 2, p. 153. 



The description of this species is very short and almost nothing is 

 kno\\Ti of its characters. It occurs in the May Hill sandstone (Siluric) 

 at Gunwick Mill, Malvern, England. 



STENASTER (?) CONFLUENS Trautschold. 



Stenaster confluens Trautschold, Nouv. Mem. Soc. Imp. Nat. Moscou, vol. 14, 

 1879, p. 11, pi. 2, fig. 5.— ScHONDORF, Palteontographica, vol. 56, 1909, p. 337. 



Based on a fragment of the distal part of a ray. Appears to be 

 a cryptozonian. Generic position unlmown. From the Upper Car- 

 boniferous (Moscovian) of Moscow, Russia. 



Genus TETRASTER Nicholson and Etheridge (emend.). 



Plate 33, fig. 4. 



Tetraster Nicholson and Etheridge, Mon. Silurian Foss. Gii-van Dist., Ayrshire, 

 fasc. 3, 1880, p. 324, pi. 21, figs. 3-8 (not figs. 1-2= Hudsonaster batheri, and 

 9-10= Urasterella girvanensis) . 



The name has reference to the four columns of actinal plates of 

 the rays. 



Remarks. — The authors of Tetraster distinguished their genus from 

 Palxaster on the giound that it had on the actinal side but four 

 columns of plates, while that genus as typified by P. matutinus, now 

 Hudsonaster matutinus, has six. In this definition they are correct, 

 but they complicated their good intentions not only by referring to 



