A MONOGRAPH OF THE EXISTING CRINOIDS 545 



Coll., vol. 60, No. 10, 1912, p. 22 (Pelew Islands, previously recorded by Hartlaub), p. 23 

 (Pitilu; description), p. 24 (compared with var. o/ro); Proc. U. S. Nat. Mus., vol. 43, 1912, p. 

 385 (identity), p. 398 (Singapore); Crinoids of the Indian Ocean, 1912, pp. 30, 34, 37 (identity 

 of previous records), p. 150 (synonymy; summary of previous records; descriptions of the types 

 of elongata and flagellata) , p. 320 (compared with D. ciliata); Proc. Biol. Soc. Washington, vol. 

 26, 1913, p. 144 (listed), p. 179 (range in east Asia), p. 181 (8 miles outside Hongkong, 14 

 fathoms; description); Smithsonian Misc. Coll., vol.61, No. 15, 1913, p. 30 (Pulau Obin); Journ. 

 Washington Acad. Sci., vol. 5, 1915, p. 214 (Malayan species; range and its significance). — 

 Habtmeter, Mitt. zool. Mus. Berlin, vol. 8, Heft 2, 1916, p. 235 (Singapore [Jagor], No. 1282; 

 Singapore [von Martens], No. 1323). — A. H. Clark, Unstalked crinoids of the Siboga-Expcd., 

 1918, p. 104 (in key; range), p. 106 (synonymy; notes; stations 43, 144, 213, 250), pp. 271, 273, 

 274 (listed). — Gislen, Kungl. Fysiogr. Sallsk. Handl., new ser., vol. 45, No. 11, 1934, pp. 20, 

 25; Kungl. Fysiogr. Sallsk. Lund Forh. vol. 7, No. 1, 1936, p. 13. 

 Dichrometra pulcher A. H. Clark, Proc. Biol. Soc. Washington, vol. 26, 1913, p. 144 (listed). 



Diagnostic features. — The longest proximal cirrus segments are about as long as 

 broad or slightly longer than broad, and the distal cirrus segments are broader than 

 long, or at least no longer than broad, and bear well-marked, though usually short, 

 dorsal spines; the division series and arm bases are more or less rugged or rugose, 

 owing to the development of more or less marked, though never exaggerated, synar- 

 thrial and articular tubercles; the lower pinnules are markedly unequal in size, but 

 none of them are especially enlarged; P 3 is 9-18 mm. long, with 21-38 (usually 25-30) 

 stout cylindrical segments, and is the longest and stoutest pinnule, markedly longer 

 than P 2 , which is 7.5-12 mm. long, with 18-27 (usually about 25) segments; P! is 

 small and weak, 4.5-11 (usually 8-9) mm. long, with up to 28 segments; the 14-40 

 (averaging about 30) arms are 65-150 (averaging about 110) mm. long. 



Description. — The centrodorsal is large, or at least moderately large, rarely of 

 medium size, thick discoidal, with more or less sloping and swollen sides or low hemi- 

 spherical, up to 7 mm. in basal diameter, with the bare dorsal pole usually flat, some- 

 times more or less deeply concave, about 3 mm. in diameter. The marginal cirrus 

 sockets are arranged in usually two or three, rarely one, irregular and closely crowded 

 rows. 



The cirri are XX-XL, 22-35 (usually 25-30), 15 to 30 (usually 15 to 25) mm. 

 long. They are usually rather stout and become laterally compressed distally. They 

 may be practically uniform throughout, or they may be somewhat more slender dis- 

 tally than proximally. The basal segments are short, and those following gradually 

 increase in length to somewhere between the sixth and the tenth, where they become 

 about as long as broad or even up to one-third again as long as broad. The next two 

 to four segments are similar, after which the length gradually decreases so that the 

 distal segments are somewhat broader than long. Often the cirrus segments are all 

 approximately subequal in size. On the eighth-twelfth (usually on the tenth oreleventh) 

 segment a small distally directed dorsal spine appears near the distal end, which in- 

 creases slightly in size for two or three segments, then remains uniform or diminishes 

 in size, and comes to lie nearer the proximal end of the segment. The dorsal spines 

 usually arise from a long base involving the distal half of the segments. The opposing 

 spine is prominent and is larger than the dorsal spines immediately preceding. 



More or less of the anterolateral angles of the radials is visible in the interradial 

 angles of the calyx, though sometimes the radials are almost entirely concealed. The 

 IBri are short, broad, strongly convex dorsalry, and almost, or quite, completely 



