210 BULLETIN 82, TTNITED STATES NATIONAL MTJSETJM 



There are 20 arms 110 mm. long. One of the IIBr series is absent, but aIIBr2 

 series (the only IIBr series not 4 [3 + 4]) bears a IIIBr 2 series internally. The 

 brachials resemble those in young individuals of C. multiradiata; the more proximal 

 are obliquely wedge-shaped, almost triangular, from half again to twice as broad 

 as long. The distal edges of the brachials are slightly produced and are armed with 

 numerous short fine spines. 



Syzygies occur between brachials 2 + 3, 13 + 14 to 30 + 31, usually in the vicinity 

 of the fifteenth brachial, and distally at intervals of from 4 to 8 (usually 7) muscular 

 articulations. 



The dorsal and lateral surfaces of the arms and division series are thickly beset 

 with very fine spines which are rather more prominent on the lateral surfaces. 



Pd is 15 mm. long, comparatively slender, and is composed of 30 segments; the 

 comb, which resembles that of C. multiradiata, consists of from 7 to 9 well-developed 

 and 3 or 4 rudimentary teeth. Pj is 14 mm. long, similar to Pd, but slightly more 

 slender. Pj is 13 mm. long, similar to Pi. P3 is 10 mm. long, resembling the pinnules 

 preceding. Pi is 8 mm. long, with a comb. Combs occur at intervals to the end of 

 the pro.ximal half of the arm. 



The mouth is radial and submarginal. The anal tube is central. The perisome 

 of the disk is naked. 



Notes. — Another specimen from Siboga station 166 has 14 arms 100 mm. long 

 and the cirri XVI, 28-30, 28 mm. long. On some of the cirri the outermost segments 

 bear dorsaUy a transverse ridge with a small but distinct spine in the center. One 

 of the IIBr series is 2, the remainder being 4 (3 + 4). 



Of the 14 specimens from Siboga station 318, one has 10 arms, two have 11, three 

 have 12, one has 13, one has 15, three have 16, one has 23, one has 25, and one has 

 30. The largest and best developed example has 25 arms 125 mm. long; the cirri 

 are from 35 to 40 mm. long. The arms borne by the 5 rays are 4, 4, 3, 3, 11; the 

 right posterior ray bears a IBr series ending in a trapezoidal ossicle from which 4 

 arms are given off, 2, side by side, from its distal (longest) face, and 1 from each 

 of the lateral faces; this segment represents 2 normal IIBr a.xillaries (with their 

 derivatives) fused, and there is a faintly indicated median dividing line. Another 

 large individual has 23 arms 125 mm. long; of the 9 IIBr series one is 2, one is 1, and 

 the others are 4 (3 + 4); the IIIBr series are all internally developed. 



The specimen from Siboga station 319 has 32 arms 85 mm. long; on every ray 

 one of the derivatives from the IBr axillary remains undivided, so that 27 of the 

 arms are borne on 5 IIBr series. 



Of the specimens from Siboga station 320, two have 10 arms, two have 12, two 

 have 13, two have 14, one has 17, one has 18, two have 21, two have 22, one has 

 23, and one has 28. One of the two with 21 arms has the anterior and right anterior 

 rays only about half the size of the others, with 4 and 5 arms, respectively; there are 

 3 IIIBr series; the arms are robust. The other with 21 arms has the arms distributed 

 on the various rays as follows: 2, 5 (4 + 1); 5 (1+4); 4 (1 + 3); 5 (4+1); one of the 

 IIBr series is 3 (2 + 3), the other three being 4 (3 + 4); all of the IIIBr series are 

 3 (2 + 3); only a single cirrus is present, the centrodorsal approaching the condition 

 of a sunken stellate plate. One of the specimens with 22 arms has the arms 130 



