A MONOGRAPH OF THE EXISTING CRINOIDS 337 



In alcohol the skeleton is pure white, the disk brownish white. 



In the second and smaller specimen, which is only indifferently preserved, the 

 centrodorsal is more flattened than in the larger. The dorsal pole is free of cirri, 

 smooth, and deeply excavated. Interradial ridges are present, though strongly pro- 

 duced only in one place. Interradial processes are well developed. 



The cirri are XXI; none of them are preserved. 



The radials are short, though always visible. The IBri are only slightly incised 

 on the distal border; they are in close lateral apposition. The IBr 2 (axillaries) have 

 only a weak posterior process. There is no ridgelike elevation of the dorsal surface of 

 the IBr series, and the synarthrial tubercle is not so strongly developed. The IIBr 

 series are more procumbent than in the larger specimen. The posterior process of the 

 IBr 2 is weak, and a synarthrial tubercle is not present as it is in the larger individual. 

 The sides of the IIBr series are sharply flattened. Most of the IIBr series are 4(3+4), 

 but one is 2. On the IIBr 2 of another postradial series of which the axillary is lacking 

 an arm has arisen through regeneration in which the first syzygy is not between brachials 

 1+2 but between brachials 31+32, the next being between brachials 53+54. There 

 are no IIIBr series. 



The 19 arms are estimated as 125 mm. long. They are smooth, as in the larger 

 specimen. The first syzygy is between brachials 1+2. As in the larger specimen 

 the second brachial is shorter than the first, and moreover lies somewhat deeper. 

 The second syzygy is between brachials 28+29 and brachials 39+40, as in the larger 

 specimen. Three poorly preserved arms show the spacing of further syzygies. On 

 one arm syzygies occur between brachials 34+35, 51+52, and 59+60; on another 

 between brachials 39+40 and 52 + 53; and on the third between brachials 33 + 34 

 and 54 + 55. The interval between the second and third syzygies is therefore from 

 13 to 21 muscular articulations. 



P D is about 8 mm. long with about 21 segments of which the first five or six are 

 large, broad, and stalked, those succeeding more or less suddenly slender and elongate. 

 Thus there is in general a basal broader section which is distinct from a more slender 

 flagellate outer section, a feature that also appears in the third Martinique specimen of 

 granulifera (see page 330). This difference is always greater than in the large specimen. 

 PI is shorter, 5-6 mm. long. The contrast between the broad basal and flagellate 

 outer sections has here already disappeared. The length of the pinnules following 

 decreases. Those immediately succeeding are about 3 mm. long; those in the middle 

 of the arms are 3^1 mm. long; these latter have, as in the larger specimen, two short 

 basal segments followed by 6 or 7 elongate ones. The gonads are slightly developed, 

 and the pinnule segments over them are, in relative fashion, modified as in the larger 

 specimen. 



The disk is 8 mm. in diameter, less deeply incised than in the other specimen. 



In alcohol the skeleton from the centrodorsal to the first brachials inclusive is 

 brownish white, the arms pure white. The disk is brownish white. 



Hartlaub said that since the two specimens. do not in all their features agree 

 either with Perissometra angusticalyx or with P. inaequalis, and the larger specimen is 

 more like P. angusticalyx, while the smaller is more like P. inaequalis, it would be 

 natural to describe one as a variety of P. angusticalyx, the other as a variety of P. 

 inaequalis. He did not do this because he considered that these two species are poorly 



