534 BULLETIN 82, UNITED STATES NATIONAL MUSEUM VOLUME 1 



The IBr series are essentially as in Antedon bifida. The IB^ are rectangular, about 

 three times as broad as long, and form conspicuous rounded synarthrial tubercles with 

 the IBr, (axillaries) , which are not quite so long as broad, being 3 mm. broad and 

 only 2.5 mm. long; the distal angle is approximately 90. 



The 10 arms are 130 mm. long. The first brachial is short and wedge-shaped, 

 twice as long exteriorly as ulteriorly, and forms a synarthrial tubercle with the larger 

 second brachial. The brachials following are more or less rectangular with only a 

 slight tendency to be wedge-shaped until after the second syzygy when they assume 

 a more triangular form. Distally the brachials become increasingly long, almost twice 

 as long as broad. The distal ends of the brachials are rather prominent and finely 

 spinous. 



Syzygies occur between brachials 3+4, 9+10, and 14+15, and distally at intervals 

 of 3 or 4 muscular articulations. 



PI is very long, measuring 17 to 19 mm., with 42 to 45 segments, of which the first 

 seven are broader than long and the distal are slightly elongated, though not much 

 longer than broad. P z is 14 mm. long, with about 32 segments, of which the distal are 

 more than twice as long as broad. P 3 is 12 mm. long, with 25 segments, of which the 

 distal are three times as long as broad; it bears a gonad. P 4 and P s are progressively 

 shorter with more attenuated and longer distal segments. The distal pinnules are 17 

 mm. long, exceedingly slender, with about 20 segments which are 3 to 4 tunes as long 

 as broad. 



The color in alcohol is yellow. 



The preceding description is based upon the original description supplemented 

 by notes on the type specimen prepared by Ailsa M. Clark. 



Locality. South of Ras Sharwein, Arabia, or northwest of Sokotra Gat. 1420' N., 

 long. 5230' E.); 2,194 meters; cable-repair ship Electra, Capt. V. F. Sparks, July 1909 

 [A. H. Clark, 1911, 1913, 1937; A. M. Clark, 1952] (1, B.M.). 



CYCLOMETRA MULTICIRRA A. H. Clark 



Cyclometra multicirra A. H. CLARK, Trans. Roy. Soc. South Africa, vol. 33, pt. 2, 1952, pp. 189-191 

 (description; Africana station 759), pis. 15, 16. 



Diagnostic features. The cirri are about LXXX when the arms are just over 100 

 mm. in length, their longest segments up to three times as long as broad; they are 

 arranged in three columns of 4 or 5 each corresponding to each radial; P! is about 15 

 mm. long, with about 33 segments; P 2 is similar but slightly longer. 



Description. The centrodorsal is conical with slightly convex sides, 3.3 mm. 

 broad at the base and 4 mm. high, with the proximal border straight. The cirrus 

 sockets are closely crowded all around the centrodorsal without division into radial 

 groups, and are arranged in three columns of 4 or 5 under each radial; the two lateral 

 columns under each radial are straight and regular, but the median column has at the 

 proximal end one or two sockets between it and a lateral column. 



The curi are LXXX, the longest peripheral 40 mm. long, with 31 segments, of 

 which the first three are broader than long, the fourth is half again as long as broad, 

 and those following increase in length to the eighth or tenth, which is from two and 

 a half to three times as long as broad, or even somewhat longer. The distal half of 

 each cirrus tapers to a rather delicate tip. The length of the segments in the distal 

 half slowly decreases so that the last five or six are only slightly, or not at all, longer 



