266 BULLETIN 82, UNITED STATES NATIONAL MUSEUM 



20+21; on the other outermost arm they are between brachials 3+4, 13 + 14, and 

 26+27. On one of the two arms arising from the IIIBr 2 series the syzygies are 

 between brachials 3+4, 10+11, and 18+19, and on the other they are between 

 brachials 3 + 4, 15 + 16, and 26 + 27. On one of the two arms arising from the IIIBr 

 2(1+2) series the syzygies are between brachials 3 + 4, 11 + 12, and 24 + 25, and on 

 the other they are between brachials 3+4, 15+16, and 27+28. The distal 

 intersyzygial interval is from 13 to 21 muscular articulations. 



P D is 6 mm. long with 21 segments of which the first is short and the second-tenth 

 are about as long as broad with prominences directed outward (toward the arm tip) ; 

 the distal segments are shorter with the inner margin provided with low knots. The 

 whole pinnule is compressed and twisted a quarter of a turn. PI is 7 mm. long, 

 with 21 segments, very much stouter and stronger than P D . The first two segments 

 taper distally, and are somewhat longer than broad. From the second segment 

 onward there is a sharply marked crest directed toward the arm tip. From the 

 sixth segment the carination branches, and from this point to the fifteenth segment 

 the pinnule is rather pronouncedly two or three edged. The sixteenth-twentieth seg- 

 ments are more rounded with thickened spinous borders distally. P s is 8-10 mm. 

 long, with 18 segments of which the first two are without out-turned prominences 

 and the remaining segments have large and very spiny processes which on the last 

 eight form a spiny garland around the distal part of the segments. This garland 

 also appears, though still more delicately developed, up to P 10 . PS is 11 or 12 mm. 

 long, with 16-18 segments. P 4 is 7-9 mm. long, with 12 segments. P u is 7 mm. 

 long, with 15 segments. P a is rather short, corresponding to P D . The longest 

 pinnule is P b . P is a little shorter than P b . The disk is without calcareous con- 

 cretions or plates. The color in life was minium red ; in alcohol it is the same but 

 fainter. 



This description is not altogether clear, but it cannot apply to any species other 

 than the one under consideration. Gisle"n discussed the relationship between varii- 

 pinna and crenulata at considerable length, but in his discussion makes no mention 

 of the differences in the proximal pinnules by which the two species are easily 

 distinguished. 



The specimens from Siboga station 273 exactly resemble others from northwestern 

 Australia. The arms are stout, basally strongly flattened laterally, and very rugose. 

 The lateral processes on the pinnule segments are very strongly developed. One very 

 fine typical example has 22 arms 120 mm. long. All the IIBr series are 4(3+4), and 

 both the IIIBr series are 2 and are internally developed. The color is white, with 

 the outer part of the pinnules and the cirri violet. Another has 20 arms 110 mm. 

 long. Two of the IIBr series are absent, the eight present being 4(3+4); the two 

 IIIBr series, both of which are internally developed, are 2. The color is similar to 

 that of the preceding, but there are in addition a few narrow purple bands and blotches 

 on the outer part of the arms. A third has 16 arms 120 mm. long. There are five 

 IIBr 4(3+4) series and one IIIBr 2 series, the latter internally developed. A fourth 

 has 16 arms 115 mm. long. There are six IIBr 4(3+4) series. The three remaining 

 examples are similar. 



