BRITISH FOSSILS. 



Decade III. Plate I. 



LEPIDASTEK GRAYI. 



[Genus LEPIDASTER {x^ti;, a scale, and ex.ffrnp, a star.) Forbes (1850). (Sab-king- 

 dom Radiata. Class Echinodermata. Order Asteriadse. Family ....?) Body de- 

 pressed, stellate, many-rayed ; rays short, tapering, covered above with polygonal ossicles ; 

 below formed of four series of oblong squamose ossicles.] 



Species Unica. Lepidaster Grayi. , 



The unique and very remarkable fossil figured in the accompanying 

 plate has been communicated by Mr. John Gray of Dudley, a gentle- 

 man to whom palseontological science is indebted for numerous and im- 

 portant discoveries among Silurian fossils, and whose splendid collection 

 has been most liberally placed at the service of all engaged in scientific 

 researches. 



At first glance it bears a striking likeness to a star-fish of the 

 genus Solaster ; its general form recalling strongly the aspect of Solaster 

 papposa. On a closer inspection the resemblance proves more apparent 

 than real, and no near affinity with that genus can be proved. On the 

 contrary, it not only possesses characters so peculiar as to establish be- 

 yond question its right to rank as a separate generic type, but even to 

 render doubtful its position among true star-fishes, and to raise the 

 question whether it be not a linking form connecting that order of 

 Echinoderms with the Crinoids. 



The disk of our fossil is a very little more than two inches in diameter. 

 It is, unfortunately, so injured that its elements cannot be clearly made 

 out, but appears to have had a framework composed of closely-set poly- 

 gonal ossicula. Around it are arranged the rays, equidistant from 

 each other, like so many spokes of a wheel. Their average length is one 

 inch and one-twelfth, and their breadth towards the base four-twelfths. 

 They are all regularly lanceolate. Their under surfaces are exposed 

 on the slab, and are composed of thick transversely oblong plates, slightly 

 overlapping each other in scale-like fashion, and ranged in four longi- 

 tudinal rows, two on each side of a central or ambulacral groove, which 

 is itself, towards the extremity, in some instances partially filled up by 



[ill. i.] B 



