188 BULLETIN 88, UNITED STATES NATIONAL MUSEUM. 



URASTERELLA HIRUDO (Forbes). 



Uraster hirudo Forbes, Mem. Geol. Surv. Gt. Britain, vol. 2, pt. 2, 1848, p. 464; 



Mem. Geol. Siirv. United Kingdom, dec. 1, 1849, p. 3, pi. 1, fig. 4; in McCoy, 



British Pal. Foss., 1851, p. 59.— Murchison, Silui-ia, 1854, p. 221, fig. 39-2. 

 Palxaster hirudo Salter, Ann. Mag. Nat. Hist., ser. 2, vol. 20, 1857, p. 326. — 



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



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

 Urasterella hirudo Forbes, in McCoy, British Pal. Foss., 1851, p. 59. 



This small species has much the appearance of being the yoimg 

 of TJ. ruthveni. The form is said to be gregarious and is associated 

 with that species. 



URASTERELLA SELWYNI McCoy. 



Urasterella selwyni McCoy, Geol. Siirv. Victoria, Prodr. Pal. Victoria, dec. 1, 

 1874, p. 42, pi. 10, figs. 2, 2a, 3, 3a. 



Original description. — "Rays five, elongate, gradually tapering from 

 a little beyond the base, which is slightly contracted, angulated on 

 the upper side by a prominent ridge along the middle of each ray, 

 having a row of conical tubercular plates (about eight in two hnes), 

 each side sloping on the dorsal aspect from the middle with about 

 tlu'ee rows of conical tubercular plates rather smaller than the middle 

 row. The five axil plates small, ovate, triangular, very tumid. 

 Adambulacral plates large, extending to the tubercular margin, 

 transversely oblong, about twice as wide as long (about nine in two 

 lines). Ambulacral plates small, in a deep ambulacral groove. 

 Length of ray from mouth to tip, six linos ; greatest width near base, 

 IJ lines. Surface of plates granular. 



"This beautiful species is easily known by its strongly angulated 

 rays on the dorsal side. The traces of oral plates are so very minute 

 and indistinct that I can not give their character. 



"This is the first fossil starfish seen in Australia, and I dedicated 

 it to my old friend Mr. Selwyn, formerly Director of the Geological 

 Survey of Victoria, and now Director of the Geological Survey of 

 Canada, who collected it. 



"This species is most nearly related to the Uraster ruthveni of 

 Forbes from the Upper Silurian grits of Kendal in Westmoreland. 



"Common in the fine sandy Silurian beds of range on E. side of 

 commonage reserve, Ealmoro." 



RemarJcs. — This is clearly a species of Urasterella. Actinally it 

 has in each axil one fairly large axillary interbrachial and in this 

 recalls the same structure in U. girvanensis, new species. 



URASTERELLA ASPERULA (Roemer). 



Asterias asperula Roemer, Palseontographica, vol. 9, 1863, p. 146, pi. 24; pi. 26, 



fig. 6; pi. 27. 



Roemeraster asperula Stijrtz, Palscontographica, vol. 32, 1886, p. 85, pi. 9, figs. 4, 5. 



Protasteracanthion primus Sturtz, Palseontographica, vol. 32, 1886, p. 90, pi. 11. 



figs. 3, 3a. 



RemarJcs. — Of this species there are two specimens in the United 



States National Museum purchased of Sturtz, and two more are 



