A MONOGRAPH OF THE EXISTING CRINOIDS 367 



pinnules. I should have said that the enlarged segments of the genital pinnules are 

 not broadened laterally as in S. hepburniana but then 1 sides are produced downward at 

 a considerable angle so that in a dorsal view they appear to be much less expanded. 

 There is a delicate median carination on the elements of the IBr series and on the first 

 two brachials which is easily traceable all along the arm. P 2 is rather more like PI 

 than like P 3 , though it is larger and has some of the characteristics of the latter. There 

 are 11-13 cirrus segments. 



Gislen wrote of the same specimen that the cirri have about 15 segments as stated 

 by Carpenter. 



Five of the specimens from the Danish Expedition to the Kei Islands station 56 

 show the following features: (1) Arms about 70 mm. long, 11-12 cirrus segments; 

 (2) arms about 70 nun. long, 12 cirrus segments; (3) arms about 55 mm. long, 12 cirrus 

 segments; (4) arms about 75 mm. long, 11-12 cirrus segments; (5) arms about 75 mm. 

 long, 11 cirrus segments. The four other specimens are similar. 



The largest specimen from Siboga station 297 is relatively large and stout with 

 the arms 75 mm. long. The surface of the dorsal pole of the centrodorsal and of the 

 radials and the IBr] is very thickly covered with irregular tubercles so that it appears 

 more or less spongelike. The borders of the ossicles of the IBr series and of the first 

 two brachials are thickened and slightly everted. The IBr 2 (axillary) has a rather high 

 median keel. The following ossicles have a prominent rounded tubercle which becomes 

 a low broad carinate process on the triangular brachials. The cirri are XVI, 12-13; 

 the longest proximal segments (the third and fourth) are slightly longer than broad, 

 and the distal segments are slightly broader than long. P! has 17-19 segments. 



Another specimen similar to the preceding but with the arms only 60 mm. long has 

 the modification of the surface of the radials and IB^ not so strongly marked. The 

 cirri are X, 12. 



A third is similar to the last, but the modification of the surface of the radials is 

 scarcely noticeable. The cirri are X, 11-12. All the others except the following 

 resemble this. 



A very interesting individual with the arms 65 mm. long has the IBri with a high 

 rounded median keel and everted lateral borders. On either side of the median keel 

 there are from two to five high rounded tubercles. The type of ornamentation as a 

 whole strongly suggests the condition found in Glyptometra tuberosa. The IBr axillary 

 has the borders slightly everted and the distal borders margined with confluent tubercles 

 which rapidly diminish in width from the median line to the outer angles. 



Localities. Siboga station 254; Kei Islands (lat. 540' S., long. 13226' E.); 310 

 meters; fine gray mud; December 10, 1899 [A. H. Clark, 1918] (1, Amsterdam Mus.). 



Danish Expedition to the Kei Islands; Dr. Th. Mortensen; station 56; 245 meters; 

 mud; May 10, 1922 (9, U.S.N.M., E. 3142; C. M.). 



Challenger station 192; near the Kei Islands (lat. 549'15" S., long. 13214'15" 

 E.); 256 meters; blue mud; September 26, 1874 [P. H. Carpenter, 1888; Hartlaub, 1895; 

 Hamann, 1907; A. H. Clark, 1907, 1909, 1912, 1913, 1918; Gislen, 1928, 1934] (1, 

 B. M.). 



Siboga station 297; Lesser Sunda Islands, north of Rotti (lat. 1039' S.,long. 12340' 

 E.); 520 meters; soft gray mud with a brown upper layer; January 27, 1900 [A. H. 

 Clark, 1918] (6, U.S.N.M., E. 418; Amsterdam Mus.). 



