612 BULLETIN 82, UNITED STATES NATIONAL MUSEUM VOLUME 1 



angle of 90. The second brachials are much larger than the first and are irregularly 

 quadrate. The distal border is everted and strongly spinous, and there are some smaller 

 spines on the inner and outer ends of the proximal border. The first syzygial pair 

 (composed of brachials 3+4) is slightly longer than broad, oblong or very slightly 

 longer interiorly than exteriorly ; the distal border is everted and strongly spinous, and 

 there is a line of lower spines just below the syzygial line. The next four brachials are 

 slightly broader than long, roughly oblong, with the central portion of the distal edge 

 everted and strongly spinous. The brachials following the second syzygy are very 

 obliquely wedge-shaped, longer than broad, with the central portion of the distal edge 

 bearing a frill of spines which gradually diminishes in width and height and disappears 

 at about the middle of the arm, though it may be represented in the outer portion of 

 the arm by a few small glassy spines on the distal edge of the brachials. The brachials 

 following the third syzygy are obliquely wedge-shaped, longer than broad, gradually 

 becoming elongated distally. 



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

 of 2 muscular articulations. 



PI is 4 mm. long, slender and gradually tapering, becoming filiform distally. It 

 is composed of 13 segments, of which the first is short, the second is about as long 

 as broad, the third is half again as long as broad, the fourth is twice as long as broad, 

 and the fifth is nearly four times as long as broad. The segments following rapidly 

 become longer, and exceedingly elongated and slender distally. The second and 

 third segments have a prominent tuft of spines on the side toward the arm tip, and 

 those following have flaring and spinous distal ends. P 2 is 3 mm. long, with 12 seg- 

 ments, of which the first is broader than long, the second is about as long as broad, 

 the third is half again as long as broad, and those following rapidly become elon- 

 gated, the distal being excessively long and slender. The second, third, and fourth 

 segments have a coarse spine on the distal dorsal end, and those following have over- 

 lapping and spinous distal ends. The pinnule is somewhat stouter basally than PI, 

 but tapers more rapidly in the basal third. The pinnules immediately following 

 appear to resemble P 2 . 



The spicules in the perisome of the pinnules are long, about two-thirds the length 

 of a pinnule segment, and are slightly bent in the middle. The proximal half, lying 

 parallel to the pinnule segment, is usually slightly swollen. The lower end is pointed. 

 The upper end carries several sharp spines of various lengths at right angles to the 

 shaft, of which the most proximal are the longest. Occasionally the first or second 

 spine on the lower side is enlarged and greatly elongated, nearly half the length of the 

 entire spicule, and recurved so that its distal end, which lies along the pinnule seg- 

 ment, is parallel to the main shaft. Very rarely the distal end of the spicule is 

 bifurcated, the bifurcation having short branches. 



The color (dry) is yellowish white, the perisome brown. 



Notes. Dr. Hubert Lyman Clark said that this seems to be a rare species for 

 it was not taken in 1938 and only once in 1939. A single specimen with arms about 

 25 mm, long and the cirri 7 or 8 mm. long was dredged at station 3435. It is easily 

 distinguished by the curious short and almost moniliform cirri. 



Locality. Atlantis station 3435; north of Caibarien, Santa Clara Province, Cuba 

 Gat. 2305' N., long. 7925' W.); 466 meters; May 2, 1939 [A. H. Clark, 1940; H. L. 

 Clark, 1941] (1, M.C.Z., 1013 [holotype]}. 



