524 BULLETIN 82, UNITED STATES NATIONAL MUSEUM 



The IBri are four times as broad as long and are laterally free. There is a weak 

 synarthrial tubercle on the articulation between the elements of the IBr series. The 

 IIBr series are 4 (3 + 4). 



The 13 arms are 65 mm. in length. The distal intersyzygial interval is 3 or 4 

 muscular articulations. 



P! has 25 segments, of which the last 6 or 7 bear teeth. P 2 is from 5.5 to 9 mm. 

 long and bears a comb with 5 teeth. P 3 and P 4 are 4.5 mm. long and bear a comb with 

 4 teeth. The first 5 pinnules have small spiny dorsal processes on the second-fifth 

 segments. Combs occur at intervals as far as the fifteenth pinnule. 



The disk is 9 mm. in diameter. The anal iuterradius has large calcareous 

 papillae. The mouth is marginal. The color in alcohol is white. 



In the specimen from Bock's station 51 the centrodorsal is thick discoidal, 10 

 mm. in diameter; the free dorsal pole is flat with somewhat raised margins, 5 mm. in 

 diameter. The cirrus sockets are arranged in from 2 to 3 rows. 



The cirri are XLII, 27-32, from 35 to 40 mm. in length. The shorter dorsal 

 cirri have 27-28 segments and the longer ventral 30-32. The first 2 segments are 

 broader than long, the third and fourth are about as long as broad, and the fifth- 

 ninth are from somewhat longer than broad to half again as long as broad. The 

 eleventh segment is again about as long as broad, and from about the fifteenth seg- 

 ment onward the segments are about twice as broad as long. Dorsal spines, which 

 are very small, in height equaling only about one-sixth the width of the segments, 

 are developed from the eleventh segment onward. The opposing spine is very 

 small, about as long as the preceding dorsal spines. The terminal claw is one- 

 quarter again as long as the preceding segment. 



The IBr] are almost completely hidden by the centrodorsal. The IBr 2 are 

 pentagonal, twice as broad as long, with the distal borders weakly concave. The 

 IIBr series are 4 (3 + 4). The IIIBr series are 2 in 8 cases out of 13. The IVBr 

 series are 4 in all 13 cases. The dorsal perisome is visible in the narrow interspaces 

 between the IIBr series and the IBr axillary. There is a distinct synarthrial tubercle 

 on the articulation between the first 2 elements of the IIBr series. The IIBr, are 

 completely united interiorly. From the IIBr 2 onward the distal edges of the ossicles 

 are everted and provided with small spines. 



The 46 arms are 130 mm. long. At the base the arms are from 3 to 3.5 mm. in 

 width, and in the middle 2 mm. The first 7 brachials are oblong, those following 

 having oblique ends and being from two to three times as broad as long. There are 

 13 or 14 brachials for each 10 mm., or 11 if the syzygial pairs are counted as units. 



Syzygies occur between brachials 3 + 4, 12+13, and 17 + 18, and distally at 

 intervals of 4 or 5 muscular articulations. 



P D is from 14 to 17 mm. in length with about 40 segments, of which 6-8 bear 

 teeth. The pinnule on the IVBr series is 10 mm. long with 32 segments, of which 

 5-6 bear teeth. P] and P 2 are of decreasing size. P 3 is 5 mm. long with about 20 

 segments, its comb consisting of 5 teeth. The small size of P 3 is not always so 

 pronounced, but P 2 or P 3 are most often the shortest. Combs occur, most often 

 on alternate pinnules, to the twentieth or twenty-fifth pinnule, and occasionally 

 even to the thirtieth pinnule. The basal segments of the pinnules are distally some- 



