228 BULLETIN 82, UNITED STATES NATIONAL MUSEUM 



P P , but slightly shorter and more slender. P 2 and the following pinnules are 7 mm. 

 long, slightly stouter than PI, composed of 20 segments, all but the first 2 or 3 of 

 which are about as long as broad. They are without terminal combs, and carry 

 gonads on the first-ninth segments. Distally the pinnules become gradually longer 

 and more slender, teaching a length of 9 mm. In the distal pinnules the first 2 

 segments are short, the third and fourth are about as long as broad, and those following 

 become progressively elongated and rather over twice as long as broad distally. The 

 segments of all but the oral pinnules have projecting and spinous distal edges. 



The color in alcohol is reddish or yellowish brown, with a dark purple medio- 

 doraal line on the arms. The specimens examined are dull yellowish white with a 

 deep brown mediodorsal line on each arm. 



Notes. Count Pourtales in his original description gave the number of arms as 10 

 and the mouth as central. He noted that the centrodorsal is slightly convex, with the 

 cirri arranged in 1 or 2 rows about the circumference. The cirri are XV-XX, 10, 

 with the segments nearly cylindrical, the third-fifth the longest, and the penultimate 

 with an opposing spine. The radials and the IB^ are visible, the latter being about 

 twice as broad as long. The IBr 2 (axillaries) are pentagonal, depressed in the center 

 into a shallow pit marked with a black spot. There is a similar pit on several of the 

 brachials, which are long, with imbricated and serrated ends. P! is much longer than 

 the succeeding pinnules. All of the pinnules are very slender with fine spines on 

 every segment, forming also a verticil at their distal ends. The spines are directed 

 forward near the beginning of the pinnules, but gradually curve back, and the last 

 segment terminates in several hooked claws. The color is rusty red with a black 

 dorsal stripe on every arm and black ambulacral furrows. 



Hartlaub reexamined the type specimen and noted that it had 1 1 arms, there being 

 present a IIBr 4 (3 + 4) series, and also that the basal segments are strongly carinate. 

 He described the IBr series as entirely free laterally. The radials and the first bra- 

 chials are not at all, or only very slightly, in contact. The brachials, except for the 

 proximal, are very long and wedge-shaped. On the articulation between two brachials 

 the dark dorsal line of the arm is broadened. 



I have also examined PourtaleV type specimen. There are 2 cirri remaining, 

 each with 10 segments. They resemble the cirri of small individuals of species of 

 Nemaster. There are 11 arms, the single IIBr series being 4 (3 + 4). The first arm 

 svzv gy is between brachials 2 + 3. The first and second segments of PD, P b and 

 P 2 have prominent high carinate processes resembling those on the basal segments of 

 the proximal pinnules in Leptonemaster; smaller, but similar, processes often occur on 

 the basal segments of the pinnules next following. There is a conspicuous and 

 rather broad median line of dark brown on the arms beyond the second brachial. 



In the specimen from the University of Iowa's Bahamas expedition as described 

 by Dr. Hubert Lyman Clark the centrodorsal is flat and discoidal, 4 mm. across. 

 There seem to have been XXI cirri, but only 9 remain. The arms are 18 in number, 

 8 being broken off. The centrodorsal and the cirri are white, while the arms are light 

 brown, with the center of the serrate distal margin of each brachial darker brown; the 

 pinnules are lighter. 



The arm fragments from Bibb station SOP undoubtedly belong to this species. 



