268 
“ Encrinus, capite stellato ramoso dichotomo, stipite pentagono, 
eqiiisetiformi. 
“ The stem and head of this animal, in its present state, measures 
about fourteen inches, the stem is about thirteen inches in height, and 
about the third of an inch in diameter, lessening a little towards the 
top : it is formed of pentagonous joints, or vertebrae, placed regularly 
over one another, which are of a testaceous substance, and united by 
very thin cartilages, as appears by examining minutely the base of the 
lowest vertebra, where it is fastened to the staiTy indentures of the joint : 
this makes the vertebrae capable of bending at the will of the animal, in 
any direction.* 
“ If we examine the five furrows or channels along the stem, we shall 
discover a small hole between every vertebra ; and in the centre of the 
base of the lowest, we shall find a small hole there, which probably 
communicates through the middle of all the vertebrae, to the cavity in 
the centre of the head. 
“ Along this stem, at different distances, from an inch and a quarter 
to a quarter of an inch in length, we observe many series of five cylin- 
drical jointed arms, each series is of equal length, and placed in a 
wheel or whirl-shaped form, like the equisetum or horse-tail plants. 
Each arm is inserted in one of the five cavities of a vertebra, and each 
joint into one another, that the upper end of one joint inclines over 
the lower end of the next to it, which it appears, at the same time, 
to inclose with a small margin. These joints are generally about one- 
twelfth of an inch in length, and the same in diameter, and have a 
* There can be little reason to doubt that the membranous substance, mentioned Page 
166 , as separated from the surface of a trochites, by the action of the muriatic acid, was 
originally of a similar nature, with the cartilage which is here described as interposed 
between the vertebrae of the pentacrinite. 
