360 BULLETIN 82, UNITED STATES NATIONAL MUSEUM 



lateral portions of the IB^ and the lateral portions of the axillary is produced outward 

 into a thin flangelike border, as are the lateral edges of the first two brachials, and of 

 the hypozygal of the first syzygial pair, and the outer edge of the epizygal. 



The 10 arms are 110 mm. long. The first two brachials are short, twice as broad 

 as long exclusive of the lateral flanges. The third brachial (the hypozygal of the first 

 syzygial pair) is oblong, about three times as broad as long. The fourth brachial 

 (epizygal) is triangular, tapering to a point on the inner side of the arm. The next 

 four brachials are triangular, about twice as broad as the median length. The ninth 

 brachial is oblong, nearly three times as broad as long, and those following are triangular, 

 about as broad as the long side, becoming distally very obliquely wedge-shaped and 

 longer. 



Syzygies occur between brachials 3+4, again from between brachials 9 + 10 to 

 between brachials 12 + 13, and distally at intervals of 3 or 4 muscular articulations. 



Pi is 7 mm. long with 22 segments, slender, tapering, and almost flagellate. P 2 is 

 shorter with 15 segments of which the first seven are short and broad, the others very 

 small. The following pinnules to P 8 or P 9 have 10 segments of which the third-seventh 

 are bluntly keeled and much expanded dorsoventrally and bear a large gonad protected 

 ventrally with large plates. The terminal segments of these pinnules are minute, 

 the basal not especially stout. The distal pinnules are 10 mm. long with 15 moderately 

 elongated segments. The ambulacra are well plated. 



The color in life is yellowish brown. 



Note. — On one of the postradial series in the type specimen there is an additional 

 element in the IBr series, a small ossicle a little more than half the size of the IBrj 

 interposed between the IBr, and IBr 2 . The first segments of the pinnules are notice- 

 able in being larger than usual, distantly suggesting the condition in the species of 

 Calometridae. 



Locality. — Albatross station 4918; Eastern Sea about 90 miles west-southwest 

 of Kagoshima Gulf; Gwaja Shima bearing S. 38° E., 34 miles distant (lat. 30°22'00" 

 N., long. 129°08'30" E.); 660 meters; bottom temperature 5.95° C; gray sand, glo- 

 bigerinae, and broken shells; August 13, 1906 [A. H. Clark, 1907, 1908, 1909, 1912, 

 1913, 1915, 1918] (1, U.S.N.M., 22629). 



History. — This species was originally described in 1907 under the name Antedon 

 scalaris from a single specimen from Albatross station 4918. Later in the same year 

 it was transferred to the new genus Poecilometra. In 190S an aberrant IBr series 

 with an additional ossicle in the type specimen was described and figured, the species 

 being given as Poecilometra acoela, and later it was listed under the same name among 

 the crinoids of Japan. 



In my revision of the families Thalassometridac and Himerometridae published 

 in 1909 Poecilometra scalaris was listed, and in my memoir on the crinoids of the Indian 

 Ocean published in 1912 it was again listed and the synonymy and range were given. 

 In my paper on the crinoids of the British Museum published in 1913 Poecilometra 

 scalaris was briefly compared with P. acoela from Challenger station 214. In 1915 

 P. scalaris was again listed as a Japanese species and the range and its significance were 

 discussed. In my memoir on the unstalked crinoids of the Siboga Expedition published 

 in 1918 scalaris was included in the key to the species of Poecilometra and the synonymy 

 and range were given. 



