PART 5 A MONOGRAPH OF THE EXISTING CRIXOIDS 747 



The color is brownish, the dorsal side "brighter" (? lighter). 



Gislen compared this specimen with one of Trichometra isis (here included in 

 Thaumatometra') and found that the latter, though larger, had much less well-developed 

 synarthrial tubercles, and much more elongated pinnule segments. Apparently 

 Mortensen's specimen closely resembles the one called Thaumatometra comaster by 

 Gislen in 1922 (here referred to T. parva) except that the latter has a large swollen gonad 

 on P 2 . Since the gonads of Mortensen's specimen are smaller, Gislen concluded that it 

 is an immature example of a much larger species of Thaumatometra, probably T. tennis, 

 since that is the only large Japanese species of the genus. However T. tennis has only 

 been recorded in Japanese waters from the northwest side of Honshu (as well as further 

 north and west) and always from soft bottoms unlike Alortensen's specimen. [NOTE 

 BY A.M.C. Mr. Clark has left no indication of his opinion on the identity of this 

 specimen but I doubt whether it should be included in tennis. Some further comments 

 are included under the headings of T. isis (p. 763) and T. parva (p. 760).] 



Localities. Albatross station 4997 ; Gulf of Tartary, off the southwestern coast of 

 Sakhalin (lat. 4738'40" N., long. 14124'30" E.); 581 meters; temperature 0.44 C.; 

 green mud; September 23, 1906 [A. H. Clark, 1907] (9, U.S.N.M., 22615, 35909, 36173). 

 Type locality. 



Albatross station 4993; off Rishiri Island, west of the northwestern end of Yezo; 

 Bomasiri Shima (off the northern end of Rubun To) bearing N. 47 E., 5 miles distant 

 (lat. 4525'30" N., long. 14053'00" E.); 259 meters; temperature 1.72 C.; gray 

 mud, sand and gravel; September 22, 1906 (1 U.S.N.M., 35911). 



Albatross station 4992; off Rishiri Island; Bomasiri Shima bearing N. 52 E., 8 

 miles distant (lat. 4524'00" N., long. 14049'10" E.); 594 meters; green mud; Sep- 

 tember 22, 1906 (1, U.S.N.M., 35912). 



Albatross station 4991; off Rishiri Island; Bomasiri Shima bearing N. 50 E., 9.2 

 miles distant (lat. 4523'20" N., long. 14048'00" E.); 594 meters; temperature 0.56 

 C.; green mud; September 22, 1906 (10, U.S.N.M., 35910). 



Albatross station 4986; off Iwanai, southwestern Yezo; Benkei Mizaki Light bearing 

 N. 35 E., 15 miles distant (lat. 4301'40" N., long. 14022'40" E.); 314 meters; 

 temperature 1.05 C.; fine black sand and black mud; September 19, 1906 (6, U.S.N.M., 

 35914). 



Albatross station 4983; off Iwanai; Benkei Mizaki Light bearing S. 2 E., 12 miles 

 distant (lat. 4301'35" N., long. 14010'40" E.); 782 meters; temperature 0.39 C.; 

 green mud; September 19, 1906 (4, U.S.N.M., 35913). 



Albatross station 4982; off Iwanai; Benkei Mizaki Light bearing S. 3 E., 10.5 

 miles distant Gat. 4300'00" N., long. 14010'30" E.); 713-782 meters; temperature 

 0.39 C.; green mud; September 19, 1906 [A. H. Clark, 1907] (1, U.S.N.M., 22616). 



Albatross station 4981 ; 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 (1, U.S.N.M., 35908). 



Rossinante station, Japan Sea, June 17, 1930; 310-315 meters [A. H. Clark, 1937]. 



Rossinante station 255; Japan Sea (lat. 4230' N., 'long. 13252' E.) ; 918-1128 

 meters; Oct. 3, 1931 [A. H. Clark, 1937]. 



Rossinante station 14; Japan Sea; 373^94 meters; Iwanow, June 8, 1931 [A. H. 

 Clark, 1937]. 



