PART 5 A MONOGRAPH OF THE EXISTING CRIXOIDS 479 



discovered there); Amer. Journ. Sci., scr. 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 Perometrinac) ; Xo. 16, p. 507 (in key; range); Unstalkcd crinoids of 

 the Siboga-F.xped., 1918, p. 234 (in key; range), p. 236 (key to the included species). — H. L. Cl.\rk, 

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

 genus). 



Diagnosis. — A genus of Peroinctrinae in which P, and Pj are always present; the 

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

 their neighbors, but their sides are never sharplj^ flattened; their lateral borders always 

 bear tubercles, one or many to each ossicle, and their distal and pro.ximal borders are 

 usually prominently everted and tubercular; prominent sjmarthrial 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. 



Batkymetrical range. — From 122 to 1040 meters. 



Thermal range—From 9.67° C. to 13.33° C. 



KEY TO THE SPECIES OF NANOMETRA 



o'. Segments of the proximal pinnules smooth, slightly tapering. 



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

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



clymene (p. 479) 

 6'. Centrodorsal conical, the dorsal pole small; cirri up to L; P, with about 10 segments (southern 



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



o'. 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 



Nanomelra 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 A^. 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; 

 Pi 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. in 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 sLxth 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 



