MONOGRAPH OF THE EXISTING CRINOIDS. 



113 



bears inwardly (to the left) a IIIBr 4(3+4) series, both derivatives from which 

 have the first syzygy between the second and third brachials, and outwardly (to the 

 right) an undivided arm in which the first syzygy is between the third and fourth 

 brachials. The total number of arms on this ray is five, arranged in 1, 1, 2, 1 order. 



Eay 3 : Two IIBr 2 series : that to the left bears externally (to the left) an 

 undivided arm, in which the first syzygy is between the second and third brachials, 

 and internally (to the right) two IIIBr series, all four derivatives from which 

 have the first syzygy between the second and third brachials ; the IIBr series to the 

 right bears two undivided arms, in which the first syzygy is between the second 

 and third brachials. The total number of arms on this ray is seven, arranged 

 in 1, 4, 1, 1 order. 



Eay 4: One of the IIBr series, that to the right, is 4(3+4), the other, that to 

 the left, 2; the IIBr 4(3+4) series bears two IIIBr 3(2+3) series; in the four 

 derivatives from these the first syzygy is between the second and third brachials 

 in all cases except on the innermost (farthest to the right) arm where it is between 

 the fifteenth and sixteenth brachials; the IIBr 2 series bears two IIIBr 2 series; 

 of these, the inner (to the left) bears two IVBr 3(2+3) series; the outer 

 (to the right) bears inwardly (to the left) a IVBr 3(2+3) series and outwardly 

 an undivided arm. In all the derivatives from this IIBr 2 series the first 

 syzygy is between the second and third brachials. The total number of arms on this 

 ray is 11, arranged in 2, 2, 4, 3 order. 



Eay 5 : Two IIBr 2 series ; that to the left bears externally (to the left) an 

 undivided arm and internally (to the right) a IIIBr 3(2+3) series; that to the 

 right bears internally (to the left) an undivided arm and externally (to the right) 

 a IIIBr 2 series, which bears internally (to the left) a IVBr 4(3+4) series and 

 externally an undivided arm. All the first syzygies in the arms of this ray are 

 between the second and third brachials. The total number of arms on this ray 

 is seven, arranged in 1, 2, 1, 3 order. 



On the arms on which the first syzygy is between the second and third 

 brachials the first brachial always bears a pinnule; but on the arms on which 

 the first syzygy is between the third and fourth brachials the first pinnule is on 

 the second brachial. 



In this specimen all but one of the IIBr series are 2, while of the ten IIIBr 

 series present five are 2, three are 3(2+3), one is 4(3+4), and one is 5(4+5). 

 In the 36 arms the first syzygy is between the second and third brachials in 29, 

 between the third and fourth in six, and between the fifteenth and sixteenth in one. 



Tabulation of the postradial series of this aberrant individual gives the fol- 

 lowing: 



