A MONOGRAPH OF THE EXISTING CRINOIDS 155 



median length, with the anterior edges concave and slightly produced and spinous; 

 after the seventh the brachials become triangular, about as long as broad, with the 

 distal edges concave. 



The first syzygy is normally between brachials 3 + 4 on the external arms, and 

 brachials 1+2 on the internal; but in many cases the first 4 brachials are grouped 

 in 2 syzygial pairs. 



Pi is 9 mm. long, very slender, with 35 short segments; the comb has 18 teeth, 

 of which the distal 10 or 11 are abruptly larger than those preceding, long and lance- 

 shaped, longer than the width of the segments which bear them. P2 is 5.5 mm. long, 

 much more slender than Pi, but otherwise similar. P3 is similar to P2, but is slightly 

 smaller and shorter. P4 is 3.3 mm. long with 17 segments, of which the distal bear 

 traces of a comb. Ps is very small and slender, 3 mm. long, with no trace of a comb. 



Notes. — In 1910 I examined the single much broken specunen from Challenger 

 station 192 in the British Museum. The cirri have 16-17 segments, of which the 

 third, a transition segment, is the longest, about three and one-half times as long as 

 its median width, and is slightly constricted centrally. The cirri are relatively very 

 long, the distal end of the second segment being nearly as far from the center of the 

 animal as the distal angle of the IIBr axillary. The outer cirrus segments have rather 

 strong dorsal processes. 



Carpenter's figure of this same specimen is essentially correct, excepting in the 

 proportions of the cirrus segments. It shows an individual larger than the one 

 described (from Siboga station 105) with a very broad discoidal centrodorsal circular 

 in outline, which is about 4 mm. in diameter. The radials are wholly and the IBri 

 are almost entirely concealed by the centrodorsal. The cirri as shown are about 

 XV, with 16 segments, and are 12 mm. long. The longest segments (fourth and 

 fifth) are drawn t\vice as long as broad basaUy, while the distal are about as broad 

 as long. 



Dr. Torsten Gisl^n has recently examined the specimen, and he writes me that 

 the cirri stand mostly in a single row; where there is a second row there is no arrange- 

 ment in definite columns. 



Localities. — Challenger starion 192; near the Kei Islands (lat. 5° 49' 15" S., 

 long. 132° 14' 15" E.); 256 meters; blue mud; September 26, 1874 [P. H. Carpenter, 

 1888; A. H. Clark, 1912, 1913, 1918] (1, B. M.). 



Sihoga station 105; near Jolo (Sulu), Philippine Islands (lat. 6° 08' N., long. 

 121° 19' E.); 275 meters; coral bottom; July 4, 1899 [A. H. Clark, 1918] (1, Amsterdam 

 Mus.). PI. 7, figs. 23, 24. 



Remarks.— In the Challenger report (p. 93) Carpenter refers to the figure of the 

 specimen from station 192 under the name of Actinometra difficilis, and says of it 

 (and also of Actinometra paucicirra) that "the two outer radials, the two distichals, 

 and the first two brachials are respectively united by syzygy." This is the only 

 reference to the name difficilis, which is not mentioned in the index. 



Later (p. 306), under the heading Actinometra pulchella, he says: 



Among the numerous comatulids which were dredged at Station 192 in the Arafura Sea was 

 a single mutilated specimen which has given me very great trouble. Three of the rays which are 

 preserved have bidistichate series, and the first two brachials above the axillaries are clearly united 

 by syzygy, the radiating ridges being very distinct on the exposed distal faces of two of the first 



