PART 5 A MONOGRAPH OF THE EXISTING CRINOIDS 519 



The 10 arms are probably at least 130 mm. long. The first brachials are short, 

 twice as long exteriorly as interiorly, and very deeply incised by the second brachials; 

 interiorly they are just in contact basally, their inner borders diverging at an angle of 

 about 45 to 60. The first syzygial pair (composed of the third and fourth brachials) 

 is oblong, and almost twice as broad as long. The next 5 brachials have slightly oblique 

 ends and are more than twice as broad as long in the median line; those after the third 

 syzygy become almost triangular, about as long as broad, and the distal become wedge- 

 shaped and finally elongate. 



Syzygies occur between brachials 3+4, 9+10, and 14+15, and distally at intervals 

 of 3 to 11 (usually 4) muscular articulations. 



P! is about 20 mm. long, tapering gradually from the base to the tip, composed 

 of 16 segments, of which the first is about twice as long as broad and the following 

 gradually become more elongate; the 5 basal segments are strongly flattened, the re- 

 mainder more cylindrical. P 2 is 15 mm. long with about 12 segments, of which the 

 first is somewhat less than half again as long as broad, the second is twice as long as 

 broad, and the following become progressively elongated. P 3 is similar, but shorter, 

 with the first segment as broad as long and the remainder proportionately shorter than 

 the corresponding segments in P 2 . ?4 and P 5 are shorter still with shorter segments. 

 The following pinnules become more slender and less flattened basally with relatively 

 shorter and more slender segments. The distal pinnules have the first segment oblong, 

 about half as long as broad, the second trapezoidal, about as long as broad, and the 

 following increasingly elongate. 



Notes. In a smaller specimen taken with that just described, the centrodorsal is 

 4 mm. broad at the base and 4 mm. high, there are only 2 or 3 cirrus sockets in each 

 column, and the brachials are relatively longer. 



Locality. Albatross station 4981 ; northeastern part of the Sea of Japan, off 

 Iwanai; Benkei Mizaki Light bearing S. 9 E., 8.8 miles distant (lat. 4258'15" N., 

 long. 14009'10" E.); 713-742 meters; temperature 0.39 C.; green mud; September 

 19, 1906 [A. H. Clark, 1907] (2, U.S.N.M., 22613, 35657). 



PSATHYROMETRA MIRA A. H. Clark 



[See vol. 1, pt. 1, figs. 98, p. 159, 228, p. 245] 



Psathyrometra mira A. H. CLARK, Proc. U.S. Nat. Mus., vol. 36, 1909, p. 648 (description; 1131'40" 

 N., 9246'40" E.; 188-220 fms.); Proc. Biol. Soc. Washington, vol. 22, 1909, p. 149 (compared 

 with Ps. gracillima) ; Proc. U.S. Nat. Mus., vol. 39, 1911, p. 562 (compared with Ps. parva); 

 Rec. Indian Mus., vol. 7, pt. 3, No. 26, 1912, p. 270 (west of Alleppey, 406 fms.; 13 miles S. by 

 W. from North Sentinel I., Andamans, 130-250 fms.; 7 miles SE. by S. from Ross I., 265 fms.); 

 Notes Leyden Mus., vol. 34, 1912, p. 140 (compared with Ps. major); Criuoids of the Indian 

 Ocean, 1912, p. 21 (intermediate between Psathyrometra and Leptometra) , p. 235 (synonymy; 

 detailed description; localities), fig. 43, p. 235; Die Crinoiden der Antarktis, 1915, p. 116 (range), 

 p. 117 (characters of the centrodorsal); Unstalked crinoids of the Siboga-Exped., 1918, p. 225 

 (in key; range), p. 227 (references; notes; stas. 45, 170), pp. 271, 273 (listed); Smithsonian Misc. 

 Coll., vol. 91, No. 4, 1934, p. 4 (compared with P. acuta) ; John Murray Exped. 1933-34, Sci. 

 Reports, vol. 4, No. 4, 1937, p. 87 (listed), p. 94 (Mabahiss sta. 109; notes; range), pp. 102, 104 

 (listed). 



Psathyrometra parva A. H. CLARK, Proc. U.S. Nat. Mus., vol. 39, 1911, p. 562 (description; Albatross 

 sta. 5284; compared with Ps. mira); Crinoids of the Indian Ocean, 1912, p. 236 (synonymy; 

 locality); Die Crinoiden der Antarktis, 1915, p. 116 (range), p. 117 (characters of centrodorsal; 

 comparison with Ps. antarctica); Unstalked crinoids of the Siboga-E\ped., 1918, p. 225 (in key; 

 range), p. 228 (references). 



