Stone Lilies of the Tre?iton Limestone, 51 



»ea, the Pentacrinus caput Mcdusce, this part of the body in covered by a 

 eimple leather-like integiunent, strengthened by small plates, and many of the 

 ancient and now extinct species were similarly constructed. The abdominal 

 plates sometimes extend down the sides, between the rays, nearly to the base^ 

 of the cup, and form a large part of the sides. The arms are composed of a 

 great number of small joints, articulating upon each other in such a manner 

 as to give the greatest amoimt of flexibility, and they are each also provided 

 on their inside, towards the mouth, with a groove, more or less deep, and 

 extending tlieir whole length. These were occupied by certain tube-like 

 vessels, which communicated with the interior, through the mouth. 



The stalk (ailled the column by pateontologists) is either round or more 

 or less pentagonal, composed of a great number of joints, and perforated 

 throughout its Avhole extent, from the cup to the base, by an alimentary 

 canal. The purpose of this channel down the centre of the column, appears 

 to have been to convey nourishment for its growth from the body. In some 

 species it was attached to the bottom by several branching roots, and in 

 others by a broad button-shaped base, consisting of a hardened exudation 

 from the alimentary canal, at the lower extremity. 



The columns of the Crinoidea, in a fragmentary state, are among the 

 most abundant of all fossils. The separated joints are to be seen in some 

 of the strata of limestone, imbedded in millions in the rock. They generally 

 occur in the shape of small circular or pentagonal plates, perforated in the 

 centre, and have been known for ages in Europe, under various names. In 

 Britain they were formerly called by the peasantry, '' St. Cuthbert's beads,'* 

 " Screw-stones," or " Pulley-stones ;" in Germany, " Rosenkranzsteine,'" 

 rosary-beads ; " Huennenthranen/' giants-tears, or " Roedersteine,'' 

 wheel-stones. Speaking of their numbers, Dr. Buckland says : " We may 

 judge of the degree to which individuals of these species multiplied among 

 the first inhabitants of the sea, from the countless myriads of their petrified 

 remains, which fill so many limestone beds of the transition formation, and 

 compose vast strata of entrochal marble, extending over large tracts of 

 country in northern Europe and North America. The substance of this 

 marble is often almost as entirely made up of the petrified bones of Encrin- 

 ites as a corn rick is composed of straws. Man applies it to construct hia 

 palace and adorn his sepulchre ; but there are few who know^, and fewer 

 still who appreciate the surprising fact, that much of this marble is com- 

 posed of the skeletons of millions of organized beings, once endowed with 

 life, and susceptible of enjoyment, which after performing the part assigned 

 to them in living nature, have contributed their remains towards the com- 

 jX)6ition of the mountain masses of the earth." 



The Crinoidea were among the first organized creatures that made theif 

 appearance in the seas of this planet, and although all the earlier species and 

 genera are extinct, yet the order still exists, and is represented by a single 

 species so fiar as is at present known, several specimeiis of which have been 

 ■procured off the coasts of Barbadoes, ^Martinique and Nevis. In a work 

 Btpou the recent and fossil species published several years since in Loudon, 



