A MONOGRAPH OF THE EXISTING CRINOIDS 443 



IBr series has a central inconspicuous small wart, and the IBr 2 (axillary) has in addition 

 two low ridges starting from the wart and running proximo-laterally. The 10 arms 

 are 70 mrn. long. A dorsal spine is developed from about the fiftieth brachial. There 

 are eight rudimentary terminal brachials. On one arm syzygies occur between 

 brachials 3+4, 9+10, 13 + 14, 19 + 20; and on another between brachials 3+4, (7 + 8), 

 14 + 15, 19 + 20, 26+27, 32 + 33, and 44+45. P, is 5.5 mm. long with 13 segments. 

 P 2 is 5.7 mm. long with 10 segments. P 3 has 11 segments. P 4 is 6 nun. long with 12 

 segments. P a has 14 segments. P b , which is of about the same length, has 11 

 segments. The distal pinnules are 7 mm. long with 10-20 segments of which the 

 first two are shorter and a little broader than those following, which are half again as 

 long as broad. The pinnules are laterally compressed and have a dorsal ridge. The 

 disk has been thrown off. 



Professor Gislen said that these specimens are closely related to A. macropoda 

 from which they differ by having almost smooth proximal brachials. The first is a 

 rather young individual with cirri shorter than the arms. The radial dorsal tubercles 

 of the centrodorsal are, however, well developed and by these it may easily be dis- 

 tinguished from A. anthus. The dorsal spines of the cirri are not so prominent and 

 pointed as in A. anthus. 



In one of the two specimens from Dr. Mortensen's station 9, according to Gislen, 

 the centrodorsal is 3.5 mm. high. The cirri are XIV, 98-103, up to SO mm. in length. 

 The radials bear a stout median tubercle. The elements of the IBr series and the 

 first 2 brachials have a weak mediodorsal carination. The 10 arms are 65 mm. long. 

 P! is 4.5 mm. long with 10 segments. P 2 is 4.5 mm. long with 10 segments. P 3 is 

 5 mm. long with 11 segments. P u is 7 mm. long with 12 segments. 



In the other specimen the cirri are 70 mm. long and the 10 arms are 75 mm. 

 long. The median carination on the elements of the IBr series and first two brachials 

 is more pronounced, on the IBr 2 (axillaries) divided into two low successive tubercles. 



Localities. Albatross station 4935; Eastern Sea, off Kagoshima Gulf; Sata 

 Misaki Light bearing N. 58 E., 4.5 miles distant (lat. 3057'20" N., long. 

 1335'10" E.); 188 meters; bottom temperature 15.89 C.; stones; August 16, 1906 

 [A. H. Clark, 1907, 1908, 1909, 1911, 1912, 1915, 1918, 1921; Sieverts, 1932] (4, 

 U.S.N.M., 22626, 35627, 35628, 36184; M. C. Z., 359). 



South of the Goto Islands (lat. 3215' N., long. 12820' E.); 183 meters; Capt. 

 H. Christiansen, April 17, 1926 (1, C. M.). 



Dr. Sixten Bock's Expedition to Japan station 12, which is the same as Dr. Th. 

 Mortensen Pacific Expedition station 9; the coral bank, Goto Islands, off south- 

 western Japan (lat. 3215' N., long. 12812' E.); 162 meters; hard bottom; May 

 15, 1914 [Gislen, 1922, 1927]. 



Geographical range. Northern part of the Eastern Sea from off Kagoshima 

 Gulf northward to the Goto Islands. 



Bathymetrical range. From 162 to 188 meters. 



History. This species was described as Antcdon macropoda in 1907 from four 

 specimens dredged at Albatross station 4935 in the previous year. Later in the same 

 year it was transferred to the new genus Ptilometra and the new genus Asteromttra 

 was tentatively suggested for its reception, a disposition that was confirmed early in 

 1908. 



