762 BULLETIN 82, tTNITED STATES NATIONAL MUSEUM VOLUME 1 



Certainly on zoogcogruphical grounds it is more likely, since the fauna of tlie southern 

 coast of Honshu appears to be quite distinct from that of the Japan Sea (Ekman, 1953), 

 though morphologically there are several characters, such as the apparently well- 

 developed sjTiarthrial tubercles on the division series and the shorter Pj, wlaich may 

 distinguish this specimen from T. parva. Unfortunatelj^ its cirri were lost. 



THAUMATOMETRA ISIS (A. H. Clark) 



Antedon isis A. H. Clark, Proc. U.S. Nat. Mus., vol. 33, 1907, p. 82 (description; Albatross sta. 4917); 



Smithsonian Misc. Coll., vol. 50, pt. 3, 1907, p. 353 (listed). 

 Thaumalometra isis A. H. Clark, Proc. Biol. See. Washington, vol. 21, 1908, p. 128 (listed); Proc. 



U.S. Nat. Mus., vol. 34, 1908, p. 233 (comparison with T. comaster); Vid. Medd. Nat. Foren. 



K0benhavn, 1909, p. 191 ("Korea"); Crinoids of the Indian Ocean, 1912, p. 246 (synonymy; 



Seaof Japan, 361 fms.; Korea) ;Journ. Washington Acad. Sci., vol. 5, 1915, No. 6, p. 215 (southern 



Japanese species; range and its significance). 

 Trichometra isis A. II. Clark, Unstalked crinoids of the 5i6o^o-Exped., 1918, p. 247 (in key; range), 



p. 248 (references) .—Gisl£n, Vid. Medd. Nat. Foren. K0benhavn, vol. 83, 1927, p. 51; fig. 42, 



p. 44 (arm and cirrus bases) . 



Diagnost-ic features. — The cirri are XXX-XIj, with about 20 segments, of which 

 the longest is little more than twice as long as broad and the distal ones are only slightly 

 longer than broad; Pi has about 20 segments; P2 and P3 are shorter with about 12 

 segments; P4 is the fu-st genital pinnule. The cirri are relatively short, only about 

 10 mm. long when the arms are 65 mm. 



Description. — The centrodorsal is hemispherical and bears between 30 and 40 

 cirrus sockets. 



The cirri are XXX-XL, 20, 10 mm. long. The longest segment, the fourth, is 

 slightly more than twice as long as broad, and the distal are only slightly longer than 

 broad. All of the segments are enlarged distally, slightly overlapping the bases of 

 those succeeding. 



The radials are visible only in the interradial angles. The IBri are narrow and 

 much ciu-ved. The IBr2 (axillaries) are about as long as broad, almost sc^uare, with 

 the four sides concave. 



The 10 arms are 65 mm. long and very slender. The first brachials are short with 

 a long outer and a short inner edge. The second brachials are irregularly quadrate. 

 The first syzygial pair (composed of the third and fourth brachials) is longer inwardly 

 than outwardly. The following brachials are shghtly wedge-shaped, becoming more 

 obliquely wedge-shaped and elongate and centrally constricted distallj'. The brachials 

 have produced and spinous distal ends. 



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

 of 2, more rarely 3, muscular articulations. 



Pi is 7 mm. long, moderately slender, composed of about 20 segments, of which 

 the basal 3 or 4 are short and the remainder are longer than broad. Po is somewhat 

 shorter, with about 12 segments, of which the proximal 4 are short and the remainder 

 are longer than broad. Pa resembles P2 and is of the same length. P4 and the following 

 pinnules bear large gonads. The distal pinnides are 9 mm. long, very slender, with 15 

 segments, of which the first 2 are short and broad and the remainder much elongated. 



Localities. — Albatross station 4917; Eastern Sea, about 90 miles WSW. of 

 Kagoshima Gulf; Gwaja Shima bearing S. 39° E., 37 miles distant (lat. 30°24' N.. 



