STRATIGRAPHICAL DISTRIBUTION. 



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Palaaster coronella, Salter. Ann. and Mag. Nat. Hist., 2d series, vol. xx, p. 326. 



" A small species, with four rows of tubercles on each arm, and a close corona of six 

 tubercles." 



Locality. — Gun wick Mill, Malvern (in the May Hill Sandstone). 



Falceaster Buthveni, Porbes. Mem. Geol. Surv., decade i, pi. i, fig. 1, 



" Body very small, in the centre of five tapering linear lanceolate, rounded rays, subcari- 

 nated on their upper surfaces, five times as long as the disc is broad. The upper surfaces of 

 both rays and disc are reticulated, indicating a structure which originally, in all probability, 

 consisted of spines grouped in tufts. The under surfaces are marked by the impressions 

 of a double series of ambulacral articulations, each slightly curved. Both these structures 

 are present in some existing antarctic forms of Uraster. The largest specimen examined 

 measured three inches and a half across, from arm-tip to arm-tip." 



Locality. — At Scalthwaiterigg, and Highthorns, Westmoreland ; in Ludlow Rocks. 

 The original specimen is in Professor Sedgwick's collection. 



Palaaster hirudo, Porbes. Mem. Geol. Surv., decade i, pi. i, fig. 4. 



"Body very minute, about a fourth as broad as the rays are long; rays tapering and linear- 

 lanceolate, contracted at their bases, pointed at their extremities. Their upper surface clothed 

 with bundles of spines arranged in regular rows, and so placed that each ray seems to be 

 marked by three or four longitudinal furrows, crossed at regular intervals by transverse 

 grooves. Under surface with short ambulacral plates and broad avenues. The largest 

 specimens do not measure more than an inch across.'' 



Locality. — Gregarious in Ludlow Rocks, at Pottersfell, near Kendal, Westmoreland. 



PalcBaster Niagarensis, Hall. Palaeontology of New York. 



Body stellate, arms tapering, ambulacra wide, under surface of the rays with large 

 marginal adambulacral plates, and five oral plates. 



Locality. — Trenton Limestone, Lower Silurian series, New York. 



A small Palceaster has been found at Braunton, near Barnstaple, N. Devon, in the 



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