236 BULLETIN 82, UNITED STATES NATIONAL MUSEUM 



slowly become elongate wedge-shaped, and later acquire a more rectangular form, 

 which is constant after about the fortieth. The elongation of the brachials is apparent 

 beyond the thirtieth. As far as the sixth the brachials are almost cylindrical, but 

 beyond that point they are always somewhat compressed laterally. Their distal 

 ends are produced. 



The first syzygy on arms arising from a IBr axillary is between brachials 3 + 4, 

 the second is usually between brachials 11 + 12, and those succeeding are separated 

 by intervals of 3 or 4 muscular articulations. In arms arising from a IIBr axillary 

 the first syzygy is between brachials 2 + 3, the next is usually between brachials 

 8 + 9, and the distal intersyzygial interval is from 3 to 5 (usually 4) muscular articula- 

 tions. The syzygial pairs are much elongated. 



In the largest specimen there is an unusually great difference in size between 

 P! and the pinnules following. It possesses the enlarged basal segments, which is not 

 the case with P 2 or P tt . In this specimen Pj is about 13 mm. long, with a comb 

 consisting of about 12 teeth. The pinnules following have no comb. In the distal 

 half of the arms the pinnules are slender and filiform, about 6 mm. in length and 

 composed of about 15 elongated segments. 



In a very slender young specimen, apparently from Blake station 155, Pj is the 

 only pinnule with enlarged basal segments, and none of the pinnules have carinatc 

 basal segments. 



In a younger specimen from Blake station 231 there are no traces of keels on the 

 basal pinnule segments, and the size relationships of the lower pinmdes are as in the 

 preceding. 



In the youngest specimen, from Blake station 155, there is no carination of the 

 basal pinnule segments, but instead there are only spinous eversions of the distal 

 ends of the segments. 



The disk is beset with calcareous concretions. The mouth is interradial. 

 The color, as preserved, is white, whitish, or brownish. The centrodorsal and 

 cirri are always white. The most striking feature of the coloration is the brown 

 upper surface of the pinmde segments which alternates with the white produced 

 and everted distal ends, so that the pinnules in dorsal view appear ringed with brown 

 and white. 



Of the 4 specimens from Montserrat, Dominica, and Martinique in the Mxiseum 

 of Comparative Zoology, which are undoubtedly the ones described by Hartlaub, 

 one has 15 arms, one is smaller, with 18 arms, and the remaining 2 are very small. 



Two specimens in the Kiel Museum collected at Barbados by Captain Werner in 

 1873 as described by Hartlaub have the centrodorsal large, flat discoidal, with the 

 cirri strictly marginal. 



The cirri are short, about XX, about 14. The first segment is short, the second 

 is already elongated, and the third-fifth are much elongated. The following seg- 

 ments decrease gradually in length, and the distal bear dorsal spines. The terminal 

 claw is very strong. The proximal portion of the cirri is cylindrical, the distal 

 laterally compressed. 



The radials are only partially visible in the angles of the calyx. The IBr t are 

 entirely visible, rather broad, free laterally, and of considerable length. The IBr 2 



