334 BULLETIN 82, UNITED STATES NATIONAL MUSEUM VOLUME 1 



broad as long, the second is broader than long with the proximal angles broadly trun- 

 cated, the third is nearly or quite half again as long as broad, the fifth is twice as long as 

 broad, and those following slowly increase in length, becoming about 3 times as long 

 as broad distally. The side of the segments toward the arm tip bears a rather broad 

 roughened line of fine spines and a slight and inconspicuous tuft of longer spines at the 

 distal end, while the distal ends of the outer segments are slightly produced and finely 

 spinous. 



P 4 is 7 mm. long with 16 segments, and resembles P 3 . 



The distal pinnules are about 15 mm. long with 25 segments which have a broad 

 roughened or minutely spinular line along the side toward the arm tip. 



Notes [BY A.M.C.]. The foregoing description is of one of the type specimens from 

 Aurora station 2. In 1938 Dr. Dilwyn John gave some supplementary descriptive re- 

 marks based on the Discovery material. The arms of the eight specimens are from 50 

 to 110 mm. long. The cirri are XL^LXV, 16-31, but mostly 24-26. The fourth to 

 seventh segments, which are the longest, are not so elongated as in the type specimen, 

 but the distal segments are longer than described, that is they are longer than their distal 

 widths. 



The distal edges of the radials are produced into a thin liplike frill which may stand 

 out at right angles or be curved farther backwards. It has the appearance of being 

 formed of a row of spines, all but the points of which are connected by a web, and it is 

 stronger on the sides than hi the midline. The distal edge of the IBri is produced into 

 a similar thorny frill. The spinous processes may be small on, or absent from, the 

 first and second brachials. They are strongest between the first and second syzygial 

 pairs, where they stand out at right angles to the arm. On the brachials beyond the 

 third syzygy they are forwardly directed but still coarse and strong. They persist to 

 the end of the arm. 



In the smallest adult specimen P, is of 25 segments, in the others of 28 to 39 seg- 

 ments and up to 12 mm. long. P 2 has from 24 to 38 segments. P 3 may be a whiplike 

 oral pinnule, with heavier basal segments than the others, but in most of the specimens 

 it is a genital pinnule. The earlier genital pinnules may be considerably shorter than 

 the orals. The number of segments in the genital pinnules varies from 14 to 23, the 

 proximal usually having a smaller number than the distal. All but the first two seg- 

 ments are longer than broad. The distal edge of each is produced into a row of spines. 

 The distal pinnules are like the genitals but slightly longer, of 20 to 30 segments. 



The disk is naked. Sacculi are abundant. In some of the specimens there is a 

 single row of small fenestrated plates along each side of the ambulacra! furrow in a few 

 segments near the tip of the pinnules. They vary in number from about two to ten 

 and when the bigger number is present, the more proximal are very small, the distal 

 larger. In some specimens there are spicules in the tentacles. Both plates and spicules 

 may be absent or one or both may be present. 



One of the smaller specimens from the Discovery collections named mawsoni by Dr. 

 John lacked the spiny processes on the proximal ossicles, as also did the three specimens 

 which he described as a separate species Florometra antarctica. In the following year 

 the more abundant material of the B.A.N.Z.A.R.E. collection convinced him that these 

 also come within the range of variation of F. mawsoni. 



One of the three type specimens of F. antarctica has the arms about 95 mm. long. 



The centrodorsal is a large rounded cone closely covered with cirrus sockets arranged 



