ASTROPECTEN. 



127 



towards the apices. This species was likewise extremely spiniferous, and possessed 

 numerous rows of spines on the margin of the ambulacral avenues, which are ai)scHt in 

 Astropecten clavafonnis. 



Locality/ and Stratiffrap Ideal Position. — Some strange blunders have been made abont 

 the rock in which this species is found. Prof. Porbes, in the memoir already qnote<L 

 calls it the Marlstone of Yorkshire, and Prof. Morris, in his ' Catalogue of British Possils,' 

 states it to come from the Lias of Yorkshire ; local collectors nearly all refer it to the 

 Calcareous Grit, and it is so catalogued in the York and other Museums. These, 

 however, are mistakes, as the sandstone from which this Star-fish is obtained belongs to 

 the Kelloway rock, which is well seen in position resting on the Cornbrash in a quarry 

 near the Leavisham station on the Whitby branch of the North-Eastern Railway. The 

 specimens are always in the form of moulds of the exterior, and in no instance has a 

 fragment of any of the ossicula been discovered. 



AsTROspECTEN Orion, Forhes. PI. X, fig. 1 a. 



AsTROPECTEN Orion, Forbes. Memoirs of the Geol. Survey, vol. ii, part 2, p. 4/8, 1848. 



— — Forbes. In Morris's Catalogue of British Fossils, 2nd ed., p. 72, 



1854. 



— — Wright. British Association Reports, vol. for 1856, p. 402, 185G. 



— — - Wright. British Oolitic Echinodermata, Paleeont. Society, p. 428, 



1860. 



Rays five, linear, lanceolate, tapering to a blunt point ; border straight, intermediate 

 angles obtuse marginal plates small, quadrate, numerous, 55- — 60 around the border of a 

 ray, each plate carries numerous small spines ; disc moderately large ; ambulacral valleys 

 wide, bounded by one or more rows of short, stout, thickly set spines. 



Dimensions. — Diameter of the disc, one inch and three quarters ; length of a ray, three 

 inches ; length across the fossil, from ray point to ray point, six inches. This specimen 

 is small and immature, and one ray is broken ; a specimen, in the British Museum, 

 measures eight inches across. 



Description. — This Star-fish is found only as a mould in a sandstone bed of the Kello- 

 way rock ; most of the specimens, beyond the mere outline of the fossil, have few details 

 preserved. In the museum of the Yorkshire Philosophical Society, however, I found a 

 specimen in which the characters of the marginal plates and spines were well preserved ; 

 this the council of the society kindly communicated for this work. Prom this mould Mr. 

 Bone obtained a very good cast in gutta percha, and from the relief and the specimen he 

 has been able to produce, the excellent figure given in PI. X a, fig. 1. 



