A MONOGRAPH OF THE EXISTING CRINOIDS 541 



In my first revision of the old genus Antedon published in 1907, stylifer was 

 transferred to the new genus Himerometra. 



On June 16, 1908, 1 described a case of distal arm division in a specimen of Hime- 

 rometra stylifer collected in Kagoshima Bay, Japan, by the United States Exploring 

 Expedition. In my list of the crinoids of Japan published on July 15, 1908, Himero- 

 metra stylifer was included. 



In my memoir on the crinoids of the Indian Ocean published in 1912, Dichrometra 

 stylifer was fisted, and the synonymy and range were given. This species had been 

 omitted from the list of forms assigned to the genus Dichrometra when that genus 

 was first established in 1909, but it was included in the list of species of Dichrometra 

 in my revision of the family Mariametridae published in 1913. 



In my report on the unstalked crinoids of the Siboga expedition pubhshed in 

 1918, Antedon stylifer was, in a footnote, erroneously placed in the synonymy of 

 Dichrometra doderleini. 



DICHROMETRA BIMACULATA (P. H. Carpenter) 



Antedon bimaculata P. H. Carpenter, Notes Leyden Mus., vol. 3, 1881, p. 186 (description; Am- 

 boina). — Bell, Proc. Zool. Soc. London, 1882, p. 532 (listed), p. 534 (specific formula). — P. H. 

 Carpenter, Proc. Zool. Soc. London, 1882 (1883), pp. 740 ft", (discussion of Bell's method of 

 formulation and corrected formula); Challenger Reports, Zoology, vol. 26, part 60, 1888, p. 

 226. — Hartlaub, Nova Acta Acad. German., vol. 58, No. 1, 1891, p. 41 (in key). — Hamann, 

 Bronns Klassen und Ordnungen des Tier-Reichs, vol. 2, Abt. 3, 1907, p. 1581 (listed). — A. H. 

 Clark, Proc. TJ. S. Nat. Mus., vol. 33, 1907, p. 131 (color), p. 150 (comparison with A. delica- 

 tissima); Notes Leyden Mus., vol. 33, 1911, p. 176 (identity); Crinoids of the Indian Ocean, 

 1912, p. 34 (identity). 



Himerometra bimaculata A. H. Clark, Smithsonian Misc. Coll., vol. 50, 1907, p. 356 (listed). 



Dichrometra bimaculata A. H. Clark, Proc. Biol. Soc. Washington, vol. 22, 1909, p. 13 (listed) ; Notes 

 Leyden Mus., vol. 33, 1911, p. 176 (identity), p. 185 (Amboina; detailed redescription) ; Crinoids 

 of the Indian Ocean, 1912, p. 34 (identity), p. 151 (synonymy; Amboina); Proc. Biol. Soc. 

 Washington, vol. 26, 1913, p. 144 (listed); Unstalked crinoids of the Siboga Exped., 1918, 

 p. 104 (in key; range). — Gislen, Kungl. Fysiogr. Sallsk. Handl., new ser., vol. 45, No. 11, 1934, 

 p. 25. 



Diagnostic features. — P 3 is much the longest pinnule on the arm, 24-25 mm. 

 long, with 30-36 segments, though it is not especially enlarged and is flexible, partic- 

 ularly distally; P 2 is nearly or quite twice as long as P,; the 36-40 arms are 100-215 

 mm. long; the cirri are XXX-XL, 25-35, up to 35 mm. long; the longest proximal 

 cirrus segments are about as long as broad or slightly longer than broad, and the 

 distal are broader than long and are either simply carinate dorsally, or bear small 

 carinate dorsal spines. 



Description of the type specimen. — The centrodorsal is a thick spreading disk 

 with a slightly hollowed dorsal surface and marginal cirri. 



The cirri are about XL, about 25. The fifth and three following segments are 

 slightly the longest. The following segments diminish slowly in size, and the penul- 

 timate has a blunt opposing spine to the terminal claw. 



The radials are just visible at the angles of the calyx. The IBr! are short and 

 are in close contact laterally. The IBr a (axillaries) are more than twice as long as 

 the IBrj and are widely pentagonal with open distal angles. The postradial series 

 may divide three times. All the division series are 2. The elements of the division 

 series are slightly raised in the middle of the articulation between them. 



