Crinoidea. lli.'l 



on the third or fourth, and still further increasing, becoming nearly 

 half again as long as broad on about the seventh; from this point 

 onward the segments very slowly decrease in length so that those in 

 the outer third of the cirri are about half again as broad as long; 

 the longer earlier segments show a tendency to be "dice-box shaped": 

 there are no dorsal spines or projections; the opposing spine is small, 

 sharp, subterminal, nearly erect; the ten arms are 27 mm long; the borders 

 of the disk are but very slightly concave in the interambulacral areas : 

 P t is 4,5 mm long with twelve segments; the first segment is about one 

 third broader than long, the second about half again as long as broad, the 

 third slightly over twice as long as broad, the following about three times 

 as long as broad; in the outer half of the pinnule the distal edges of the 

 segments project slightly dorsally; the pinnule is moderately stout basally, 

 and tapers evenly and gradually to the tip, not being flagellate distaliy ; 

 it is more or less rounded-prismatic; P 2 is 3 mm long with twelve seg- 

 ments, smaller and weaker than P l5 with shorter segments; P 3 is 3 mm 

 long and resembles P 2 ; the following pinnules do not increase in length, 

 but become very slender; syzygies occur between the third and fourth 

 brachials, again between the seventh and eighth and twelfth and thirteenth, 

 and distally at intervals of two oblique muscular articulations. The colour 

 is deep purple, the centrodorsal and cirri white. 



The two other specimens are similar, but slightly smaller ; one has the 

 cirri very slightly purplish at the tip, and the other has a white medio- 

 dorsal line on the arms. 



The essential features presented by these little animals are as fol- 

 lows : the coefficient of variability between the three specimens is very 

 high, indicating immature forms with a quite different adult stage. P t is 

 more or less prismatic, showing that the animal belongs to the Oligo- 

 phreata; in that group it comes nearest to P t in Ptilometra with which it 

 agrees in all particulars even though the following pinnules are smaller 

 instead of larger. The cirri are evidently immature ; their distal taper, 

 great length, and large number of segments, as well as the proportions of 

 the segments, agree with the conditions found in Ptilometra macronema, 

 though they are white, and in PL macronema the cirri are the darkest part 

 of the animal. The outer pinnules have comparatively short segments, 

 which shows that the animals can not belong to any group but the 

 Charitometridae, Calometridae or Thalassometridae and, except for the lack 

 of carination and the juvenile characters they come nearest to the pinnules 

 of Ptilometra macronema. 



