PART 5 A MONOGRAPH OF THE EXISTING CRINOIDS 515 



area is invariably 3, though they may be closely crowded or more or less widely 

 separated. 



It is almost certain that all the specimens mentioned above represent a single 

 species, though it might be possible to consider those from Albatross stations 4230 

 and 5032 (southeastern Alaska and Yezo Strait, in 197 to 974 meters) as representing 

 typical fragilis, and the remainder, all of which are from depths of more than 1200 

 meters, as representing a forma borealis. 



Localities. Albatross station 4537; Monterey Bay, California; Point Pinos Light 

 House bearing S. 74 E., 7.4 miles distant; 1574-1941 meters; temperature 3.61 C.; 

 hard sand and mud; May 31, 1904 [A. H. Clark, 1915] (57, U.S.N.M., 35784). 



Albatross station 3342; off the Queen Charlotte Islands, British Columbia Gat. 

 5239'30" N., long. 13238'00" W.); 2903 meters; temperature 1.83 C.; gray ooze 

 and coarse sand; September 3, 1890 [A. H. Clark, 1908] (2, U.S.N.M., 22669, 35742). 



Albatross station 4230; Behm Canal, southeastern Alaska, in the vicinity of 

 Naha Bay; Indian Point bearing N. 70 E., 5 miles distant; 197-439 meters; 

 temperature 5.78 C.; rocky bottom; July 7, 1903 [A. H. Clark, 1918, as alascana] 

 (11, U.S.N.M., 35787). 



Albatross station 4780; east of Agattu Island, Aleutians (lat. 5201'00" N., long. 

 17439'00" E.); 1912 meters; temperature 2.17 C.; gray mud, sand and pebbles; 

 June 7, 1906 [A. H. Clark, 1908] (1, U.S.N.M., 22670). 



Albatross station 5032; Yezo Strait, between Yezo and Kunashir, Kuriles (lat. 

 4405'00" N., long. 14530'00" E.); 548-974 meters; temperature 1.61-2.17 C.; 

 brown or green mud, fine black sand and gravel; September 30, 1906 [A. H. Clark, 

 1907] (4, U.S.N.M., 22614, 35739, 36199). Type locality. 



Albatross station 5082; Suruga Gulf, Japan; Omai Said Light bearing N. 22 E., 

 33 miles distant Gat. 3405'00" N., long. 13759'00" E.); 1210 meters; temperature 

 3.17 C.; green mud, fine sand and globigerinae; October 20, 1906 (part of an arm 

 and most of a cirrus, U.S.N.M., 35925). 



Geographical range. From Monterey Bay, California, northward to Alaska, 

 thence westward to the western Aleutian Islands and southward to southern Japan. 



Bathymetrical range. From 439 (?197) to 2903 meters; the average of 6 records 

 is 1299 meters. 



Thermal range. From 1.61 to 5.78 C.; the average of 6 records is 2.91 C. 



Remarks. As at present understood Psathyrometra fragilis, described in 1907, 

 includes as synonyms Ps. borealis and Ps. profundorvm described in 1908, and Ps. 

 alascana inserted in the key to the species of Psathyrometra given in the Siboga report 

 in 1918. 



All of the known specimens have been dredged by the Albatross. 



PSATHYROMETRA BIGRADATA (HarUaub) 



[See vol. 1, pt. 2, pi. 11, fig. 1028] 



Antedon bigradata HARTLAUB, Bull. Mus. Comp. Zool., vol. 27, No. 4, 1895, p. 145 (description; 

 Albatross stas. 3358, 3404), pi. 1, fig. 5. H. L. CLARK, Proc. Washington Acad. Sci., vol. 4, 1902, 

 p. 522 (from Hartlaub). HAMANN, Bronn's Klassen und Ordnungen des Tier-Reichs, vol. 2, 

 Abt. 3, 1907, pp. 1578, 1580 (listed). 



Psathyrometra bigradata, A. H. CLARK, Smithsonian Misc. Coll., vol. 50, pt. 3, 1907, p. 353 (listed) ; 

 Bull. Mus. Comp. Zool., vol. 51, No. 8, 1908, p. 240 (arm fragments from Albatross sta. 2818 

 possibly belong to this species); Proc. U.S. Nat. Mus., vol. 34, 1908, p. 222 (compared with 



