46 



INTRODUCTION TO ZOOLOGT. 



vertebras are vvell described by the common English name of 

 " wheel-stones." " The perforations in the centre of these 

 joints, affording a facility for stringing them as beads, has 

 caused them, in ancient times, to be used as rosaries.* In 

 the northern parts of England, they still retain the appellation 

 of St. Cuthbcrt's beads." Sir Walter Scott has, -with his 

 usual felicity, refeiTed to the circumstance in his poem of 

 Marmion : — 



" But fain St. Hilda's nuns would learn 

 If, on a rock by Liiidisfarn, 

 St. Cuthbert sits, and toils to frame 

 The sea-born beads that bear his name." — Canto II. 



The race of Crinoid Star-fishes was believed to be altogether 



extinct in European seas, when, 

 in 1823, Mr. J. V. Thompson 

 announced the discoveiy, in the 

 Cove of Cork, of a diminutive 

 species measuring only three- 

 quarters of an inch in length. In 

 1836, the same gentlenif.n pro- 

 claimed that this was the young 

 state of the Star-fish known as 

 the Piosy-feather-star (Comatula 

 rosacea, Fig. 31). The actual 

 change of the animal, from its 

 fixed and pedunculated state into 

 its free condition, had not actually 

 been seen by this intelligent ob- 

 server. But at length the matter 

 was placed beyond any possibility 

 of doubt. 



"When dredging," says Pro- 

 fessor Forbes, "in Dublin Bay, 

 in August, 1840, with niv friends 

 Mr. Pt. Ball and Mr. W.'Thomp- 

 son, we found numbers of the 

 Phytocrinus or polype state of 

 the Feather-star, more advanced 

 than they had ever been seen 

 before ; so advanced that we saw 

 the creature drop from its stem, and swim about a true 

 * Buckland's Bridgewater Treatise, vol. i. page 424. 



Fig. 31.— Polype state or tbe 

 Fbather-star (magnified). 



