6 



Bradford Clay and its Fossils. 



Terebratula flabellum, Terebratula fwcata, 



rare and beautiful forms, found in the section at the end of the Box tunnel. 



But of all the inhabitants of this ancient sea, the Apiocrinus to 

 which I have before alluded, deserves especial notice, as it was at 

 this period of the earth's history, that it attained its greatest de- 

 velopernent, both in size and numbers. The species most abundant 

 here was the Apiocrinus Parkinsoni — Parkinson's pear-like lily- 

 shaped animal. It belongs to the highest class of the Radiata, the 

 Echinodermata, and derives its name from the resemblance of its 

 body to a pear. In its perfect state, its ten feathery arms gave the 

 Apiocrinus somewhat the appearance of a star-fish, growing on a 

 tall flexible stem (see woodcut). But to descend to more minute 

 detail, the animal consisted, 1st — of a solid root, formed of many 

 layers of calcareous stony matter deposited round the base of the 

 stem, as may be seen in a section. 2nd — of a long stem, composed 

 of about 150 circular discs, with radiated surfaces. In old speci- 

 mens, the stem was from 10 inches to a foot in length. The de- 

 tached discs were described by old authors as Entrochi, or wheel 

 stones, they were also popularly called "giant's tears," fairy stones, 

 &c; and as each is perforated in the centre, they were used as rosaries, 

 hence in the North of England, joints of some of the species of 

 Encrinites are still known as St. Cuthbert's beads, 1 in this part of 

 the country they are vulgarly called "coach-wheels." 3rd — The 

 body. The upper plates of the stem gradually increased in thick- 

 ness and diameter, so as to form the elegant vase shaped body of 

 the creature, towards the middle of which, the circular plates were 

 succeeded by a more complicated structure, consisting of a set of 

 five angular basal plates, two sets, of five each, of intermediate plates, 



1 "On a rock by Lindisfarn, 



St. Cuthbert sits and toils to frame 



The sea borne beads that bear his name." — Marmion. 



