PART 5 A MONOGRAPH OF THE EXISTING CRINOIDS 479 



discovered there); Amer. Journ. Sci., ser. 4, vol. 32, 1911, p. 129 (characteristic of the Japanese 

 fauna; significance) ; Crinoids of the Indian Ocean, 1912, p. 17 (only known from southern Japan), 

 p. 62 (in key), p. 241 (original reference; type); Journ. Washington Acad. Sci., vol. 7, 1917, 

 No. 5, p. 127 (referred to Perometrinae); No. 16, p. 507 (in key; range); Unstalked crinoids of 

 the Siboga-'Exped., 1918, p. 234 (in key; range), p. 236 (key to the included species). H. L. CLARK, 

 Echinoderm fauna of Australia, 1946, p. 60 (in key), p. 61 (type species; mainly East Indian 

 genus) . 



Diagnosis. A genus of Perometrinae in which P t and P 2 are always present; the 

 elements of the IBr series and the first 2 brachials may be laterally just in contact with 

 their neighbors, but their sides are never sharply flattened; then- lateral borders always 

 bear tubercles, one or many to each ossicle, and their distal and proximal borders are 

 usually prominently everted and tubercular; prominent synarthrial tubercles are not 

 developed; and the interradial and interbrachial portions of the perisome are without 

 calcareous nodules. 



Type species. -Antedon minor A. H. Clark, 1907, preoccupied; a synonym of A. 

 bowersi A. H. Clark, 1907. 



Geographical range. From southern Japan, the East Indies, and southeast 

 Australia. 



Bathymetrical range. From 122 to 1040 meters. 



Thermal range. From 9.67 C. to 13.33 C. 



KEY TO THE SPECIES OF NANOMETRA 



a 1 . Segments of the proximal pinnules smooth, slightly tapering. 



6'. Centrodorsal broadly truncated with a wide, nearly flat dorsal pole; cirri about LXX; P, with 

 14-20 segments (Kei Islands, northern Celebes and the Moluccas; 204-1040 meters). 



clymene (p. 479) 

 b 2 . Centrodorsal conical, the dorsal pole small; cirri up to L; PI with about 10 segments (southern 



Japan; 254-349 meters) bowersi (p. 483) 



a 2 . Segments of the proximal pinnules with conspicuously spinous distal ends (Tasmania and Bass 

 Strait; 122-174 meters) johnstoni (p. 485) 



NANOMETRA CLYMENE A. H. Clark 



FIGURE 23 



Nanometra clymene A. H. CLARK, Notes Leyden Mus., vol. 34, 1912, p. 143 (description; Siboga sta. 

 253); Unstalked crinoids of the Siboga-Exped., 1918, p. ix (relationship with N. bowersi), p. 237 

 (in key; range; detailed description; stas. 173, 251, 253, 254), p. 274 (listed), pi. 26, fig. 84. 



Diagnostic features. The Centrodorsal is broadly truncated with a wide, more or 

 less flat, dorsal pole; the cirri are about LXX when the arms are 70-120 mm. long; 

 P! has 14 to 20 segments which are smooth and slightly tapering. 



Description. The Centrodorsal is truncated conical, 3.3 mm. in diameter at the 

 base and 2.6 mm. hi vertical height; the bare almost flat dorsal pole is 2.0 mm. in 

 diameter. The cirrus sockets are arranged in 4 or 5 closely crowded regularly alter- 

 nating rows, or 4 closely crowded alternating columns in each radial area. 



The cirri are about LXX, 43-47, from 25 to 30 mm. long, moderately slender. 

 The first segment is very short, the second is about twice as broad as long or even some- 

 what broader, the third is nearly as long as broad, the fourth is about a third again 

 as long as broad, the sixth to eleventh or twelfth are about twice as long as broad ; 

 the following segments gradually decrease in length so that the last 10 or 11 before the 



