298 BULLETIN 82, UNITED STATES NATIONAL MUSEUM 



17-19) arms are 105-180 mm. long. P 2 and P 3 have 26-31 segments; P 3 is usually, 

 though not always, longer than P 2 . 



Description. The centrodorsal is large, slightly convex, with the dorsal pole 

 often finely pitted. The cirrus sockets are arranged in two irregular rows. 



The cirri are about XXV, 35-40, about 35 mrn. long; none of the cirrus segments 

 are longer than broad; the outer bear small dorsal tubercles, and the terminal some- 

 tunes prominent spines. 



The radials are plainly visible in the angles of the calyx, or entirely concealed. 

 The IBri are entirely united laterally. The IBr 2 (axillaries) are short and pentagonal. 

 The IIBr series are usually 4(3+4), more rarely 2. IIIBr series, usually developed 

 only ulteriorly, are 2, but 4(3+4) when following a IIBr 2 series. Synarthrial 

 tubercles are moderately developed. The division series are laterally free, though 

 sometimes very close together. 



The 16-22 elongated arms are 180 mm. long, some of them arising direct from 

 the IBr axillaries. The brachials are short; the first is shorter than the second; the 

 first syzygial pair (composed of brachials 3+4) is very short; following this there is 

 a series of discoidal brachials, and then a series of wedge-shaped brachials, the latter 

 becoming progressively shorter, and short-oblong after the middle of the arm. The 

 brachials are only slightly overlapping. The bases of the arms are rugose. 



Syzygies occur between brachials 3+4, again somewhere between the eleventh 

 and nineteenth brachials, and distally at intervals of from 7 to 11 muscular ar,ticu- 

 lations. In the arms arising directly from a IBr axillary the second syzygy is between 

 brachials 9 + 10, more rarely between brachials 16 + 17, and the distal intersyzygial 

 interval is usually 7 or 8 muscular articulations. 



P t or P D is 8 or 9 mm. long. P 2 is usually much longer, 18 mm. long, almost as 

 long as P 3 . P 4 is variable, but usually smaller. The following pinnules decrease in 

 length to P 7 , which is 7 or 8 mm. long. The distal pinnules are 14 mm. long. The 

 proximal segments of the pinnules in the basal third of the arm are strongly carinate. 

 The enlarged lower pinnules are moderately stiffened. P 2 is composed of about 20 

 sharply carinate segments, none of which are longer than broad. P D and P! are very 

 slender and flagellate after the first few segments. 



Notes. The specimen from the Danish Expedition to the Kei Islands station 90 

 has 19 arms 165 mm. in length. The cirri have 34-36 segments. P 3 has 29 segments. 

 P 4 is smaller with 26 segments. On one arm the thirty-second brachial bears an 

 irregular series of small ossicles which collectively serve as an axillary ; beyond this 

 the main arm continues at a slight angle and another arm, of almost the same size, 

 extends outward dorsally at right angles to the main arm stem. 



In one of the specimens from the Danish Expedition to the Kei Islands station 

 31 there are 21 arms; the 10 IIBr series are all 4(3+4) and there is a single IIIBr 

 2 series developed internally. Another specimen has 19 arms; of the nine IIBr 

 series present eight are 4(3+4) and one is 2. The cirri are XVIII, 31-33. A third 

 example has 18 arms; of the eight IIBr series present one is 4(3+4), six are 2, and one 

 consists of a single axillary only. The cirri are XVIII, 28-31. The fourth specimen 

 has 13 arms, there being 3 IIBr 4(3+4) series. The cirri are XVII, 28-30. 



One of the specimens from the Danish Expedition to the Kei Islands station 38 

 has 22 arms 110 mm. long. There are 10 IIBr 4(3+4) series and two IIIBr 2 



