178 THE AQUARIAN NATURALIST. 



known, not above half a dozen in the whole have 

 found their way to Europe : of these, one is in the 

 National Museum at Paris, from Martinique ; one in 

 the British Museum, taken off Nevis ; one in the 

 Hunterian Museum in the Glasgow College, from 

 Barbadoes ; one in the Museum of the Royal College 

 of Surgeons in London ; and one in that of the Geo- 

 logical Society. 



The West Indian species (Pentacrinus Caput Me- 

 dusa] , and that described by Mr. Thompson, are, in 

 fact, the only existing species hitherto discovered; 

 the first of these is an animal of considerable size, its 

 jointed stem thicker than a swan's quill, rising to the 

 height of several feet, and the spread of its arms being 

 equal to a span*. The latter, on the contrary, is 

 probably the smallest of the tribe, not exceeding, 

 when full-grown, three-quarters of an inch in height, 

 and slender in proportion ; and doubtless it was owing 

 to this minute size that it so long escaped the prying 

 eyes of the most industrious naturalists. 



The pedicle or stem of this little zoophyte is not 

 thicker than a piece of sewing-silk, being but slightly 

 enlarged towards its upper end. It is composed of a 

 variable number of joints (about twenty-four in full- 

 grown specimens), which are shorter as they approach 

 its upper part, until, immediately adjoining the body, 



* The dimensions of the largest recent Pentacrinus Caput 

 Medusae are very humble when compared with some of their 

 fossil congeners. We have before us at the present moment 

 some dozens of specimens from the limestone rocks of Derby- 

 shire, whose stems measure at least an inch in diameter, and 

 which when complete were perhaps ten or twelve feet high. 



