OF ARTS AND SCIENCES. 27 



Second primary radials five ; they are very minute, luiiette-formed, 

 less than a semicircle, slightly depressed at their upper margin. 



Third primary radials, five ; small, leaf-like, resting upon the second 

 radials, spreading beyond them, the outer margin expanding upward. 

 The centre of the pieces is prolonged upward into a little tongue- 

 like figure ; on either outer margin is also a prolongation about half 

 as wide as the centre one, and of nearly equal height, leaving a 

 deep, square-like notch on each side of the centre prolongation of the 

 pieces. 



First secondary radials. These pieces are ten in number, two to 

 each third primary radial ; they are similar in form and size, about as 

 high as wide, fitting into the indentations on either side of the third 

 primary ; they rise a little over one third of their height above the 

 centre prolongation of the primary to which they are joined, are trun- 

 cated obliquely downward and outward from their junction with 

 each other ; the outer max'gins falling into, and further expanding, 

 the somewhat circular outline of the second and third primary 

 radials. 



Second secondary radials. Ten in number, resting on the bevelled 

 upper margins of the pieces below them, nearly as high as wide, 

 deeply indented for the reception of the first brachial pieces, thus 

 divided into three tongue-like points, not unlike the centre point of the 

 third primary, and two oblong circular depressions ; each division of the 

 upper margin of the pieces occupying about one fifth of its length ; 

 they are joined together by a straight line continuous with that mark- 

 ing the junction of the pieces immediately below them. 



Arms. Twenty, delicate, three times as long as the calyx, each 

 ray supporting four ; they are non-bifurcate, composed of about six 

 thin, irregular, oblong pieces above the first brachial, where they are 

 composed of a double row of very thin pieces, joined in the centre 

 of the arms by angular points, which fit into the alternate depressions 

 on either side, the junction forming a serrated line; each of the pieces 

 forming the double row composing the arms bears a long filamentous 

 cilia, which is composed of very minute pieces, the length of which is 

 about equal to their diameter. 



Inter-radial pieces. Between each group of four arms, and rising 

 in the notch between the first radials, are three, sometimes four, small 

 inter-radial pieces ; the first is pentangular, widest below the centre 

 of the inferior margin, angular, the superior margin a horizontal line ; 



