PART 5 A MONOGRAPH OF THE EXISTING CRINOIDS 63 



6'. P3 with more than 18 segments. 



cK Pi 3.5 mm. long when the arms are up to 45 mm.; Pj about three-quarters that length (Mada- 

 gascar and Mauritius to the Maldive Islands; littoral) mauritiana (p. 69) 



c'. Pi 10 mm. long when the arms are 40 mm.; P2 less than half as long (Celebes). 



andromacha (p. 71) 

 6-. Pj with up to 16 segments. 



c'. P3 more than twice as long as Pi and P2, with about twice as many segments; 10-14 (usually 

 10-12) cirrus segments (Philippine, Benin, and Tonga Islands to northern Australia and 



westward to the Andaman and Nicobar Islands; 0-54 meters) nana (p. 71) 



C-. P3 not more than a third again as long as Pi and P2, with not more than a third again as 

 many segments; 9-17 (usually 11-14) cirrus segments (south and southwestern Japan; 

 108-728 meters) briseis (p. 75) 



DOROMBTRA PARVICIRRA (P. H. Carpenter) 



[See vol. 1, pt. 2, fig. 789, p. 366] 



Antedon parvicirra P. H. Carpenter, Challenger Reports, Zoology, vol. 26, pt. 60, 1888, p. 204 

 (description; Challenger Sta. 208), pi. 36, figs. 7, 8. — A. H. Clark, Smithsonian Misc. Coll., 

 vol. 50, pt. 3, 1907, p. 352 (belongs with the A. bifida type), p. 353 (listed). — Hamann, Bronn's 

 Klassen und Ordnungen des Tier-Reichs, vol. 2, Abt. 3, 1907, p. 1579 (listed). — A. H. Clark, 

 Crinoids of the Indian Ocean, 1912, p. 34 ( = Iridomelra parvicirra). 



Iridometra parvicirra A. H. Clark, Proc. Biol. Soc. Washington, vol. 21,1908, p. 131 (listed); Proc. 

 U.S. Nat. Mus., vol. 34, 1908, p. 218 (compared with /. lArgijrometra] crispa); vol. 39, 1911, 

 p. 559 {Albatross Sta. 6355); vol. 40, 1911, p. 42 (cirri compared with those oi I . aegyptica) 

 Crinoids of the Indian Ocean, 1912, p. 34 {=A. parvicirra P. H. Carpenter, 1888), p. 231 (syno- 

 nymy; localities); Smithsonian Misc. Coll., vol. 61, No. 15, 1913, p. 54 (comparison with 

 aegyptica). 



Iridometra scita A. H. Clark, Smithsonian Misc. Coll., vol. 52, pt. 2, 1908, p. 232 (Philippines); 

 Crinoids of the Indian Ocean, 1912, p. 231 (synonymy; Philippines; Billiton); Smithsonian Misc. 

 Coll., vol. 61, No. 15, 1913, p. 54 (Billiton; Macclesfield Bank, 35-41 fms.).— Gisl^n, Kungl. 

 Fysiogr. Sallsk. Lund Forh., vol. 7, No. 1, 1936, p. 4 (Macclesfield Bank). 



Iridometra sp. A. H. Clark, Crinoids of the Indian Ocean, 1912, p. 232 (Albany Passage, Queensland). 



Dorometra parvicirra A. H. Clark, Journ. Washington Acad. Sci., vol. 7, 1917, No. 5, p. 128 (listed); 

 Unstalked crinoids of the Siboga-Exped., 1918, p. 215 (in key), p. 216 (synonymy; notes; Sta. 99), 

 p. 272 (listed); Smithsonian Misc. Coll., vol. 72, No. 7, 1921, pi. 2, fig. 18 (ambulacral deposits) . — 

 GiSL^N, Nova Acta Reg. Soc. Sci. Upsaliensis, ser. 4, vol. 5, No. 6, 1922, p. 5, p. 137 (localities; 

 notes), p. 182 (listed); figs. 125-127, p. 134; Kungl. Fysiogr. Sallsk. Lund Forh., vol. 7, No. 1, 

 1936, p. 4 (Macclesfield Bank). — H. L. Clark, Mem. Mus. Comp. Zool., vol. 55, 1938, p. 46 

 (Darwin); Echinoderm fauna of Australia, 1946, p. 62 (in key; references; distribution). 



Diagnostic features. — P2 is intermediate in size and in the number of its component 

 segments between Pj and P3; the cirri have up to 17 segments and are not especially 

 slender, their longest segments being not more than twice as long as the width of the 

 expanded ends; Pi has 10 to 15, Pj 13 or 14 or more, and P3 17 to 19 segments. The 

 size is large for a species of this genus, the arms being from 50 to 60 mm. in length, 

 and the general habitus is robust. 



Description of the holotype [from Carpenter, modified by A.M.C.]. — The centrodorsal 

 is flattened hemisphei'ical, 1.9 mm. in diameter, with a few small papillae around the 

 flat dorsal pole. There are about XL cirrus sockets. A peripheral cirrus S mm. long 

 has 13 segments most of which are constricted centrally and flared at the ends, particu- 

 larly the distal ends. The longest segments are two and a half times as long as their 

 median widths and the antepenultimate segment is one and a half times as long as 

 wide. The opposing spine is slender and prominent. 



The division series are widely separated laterally. 



