A MONOGRAPH OF THE EXISTING CRINOIDS 389 



volumes the synonymy and habitat were given. In the Siboga report it was included 

 in a key to the species of Amphimetra. 



Seven additional specimens from Singapore belonging to the British Museum 

 were recorded in 1929. 



AMPHIMETRA LAEVIPINNA (P. H. Carpenter) 



Plate 38, Figures 175, 176 



Antedon laevipinna P. H. Carpenter, Journ. Linn. Soc. (Zool.), vol. 16, 1882, p. 502 (description; 

 Canton, China); Proc. Zool. Soc. London, 1882 (1883), p. 746; Challenger Reports, Zoology, 

 vol. 26, pt. 60, 1888, p. 206 (in key).— Hartlatjb, Nova Acta Acad. German., vol. 58, No. 1, 

 1891, p. 81 (discussion; considered a synonym of milberli). — Hamann, Bronns Klassen und 

 Ordnungen des Tier- Reichs, vol. 2, Abt. 3, 1907, p. 1580 (listed).— A. H. Clark, Proc. U. S. 

 Nat. Mus., vol. 34, 1908, p. 479 (listed); Smithsonian Misc. Coll., vol. 60, No. 10, 1912, p. 2 

 ( = Amphimetra laevipinna); Crinoids of the Indian Ocean, 1912, p. 34 (of P. H. Carpenter, 

 1888 = Amphimetra milberti). 



Himerometra schlegelii A. H. Clark, Proc. Biol. Soc. Washington, vol. 21, 1908, p. 223 (10-armed 

 specimen). 



Amphimetra milberti (part) A. H. Clark, Proc. Biol. Soc. Washington, vol. 22, 1909, p. 7 (listed); 

 Crinoids of the Indian Ocean, 1912, p. Ill (record from Canton, China). 



Amphimetra schegelii (part) A. H. Clark, Proc. Biol. Soc. Washington, vol. 22, 1909, p. 7 (listed). 



Amphimetra schlegelii (part) A. H. Clark, Vid. Medd. Naturh. Foren. K0benhavn, 1909, p. 158 

 (10-armed specimen); Crinoids of the Indian Ocean, 1912, p. 111. 



Amphimetra laevipinna A. H. Clark, Smithsonian Misc. Coll., vol. 60, No. 10, 1912, p. 2 ( = Antedon 

 laevipinna P. H. Carpenter), p. 15 (compared with A. schlegelii and with A. philiberti; northern 

 representative of the discoidea group), p. 17 {=milberli, in part, of P. H. Carpenter, 1888. and 

 Hartlaub, 1891; = schlegelii, in part, of A. H. Clark, 1908, 1909; Canton, China; detailed descrip- 

 tion of the type and of another from an unknown locality) ; Proc. Biol. Soc. Washington, vol. 

 26, 1913, p. 179 (range in east Asia); Journ. Washington Acad. Sci., vol. 5, 1915, p. 214 (Malayan 

 species; range and its significance); Unstalked crinoids of the Siboga-Exped., 1918, p. 83 (in 

 key; range), p. 88 (references; localities from which known). — Mortensen, Hong Kong Nat., 

 Suppl., No. 3, 1934, p. 5 (Canton). — Gislen, Kungl. Fysiogr. Sallsk. Handl., new ser., vol. 45, 

 No. 11, 1934, p. 48 (extends to southern Japan). 



Amphimetra schleegelii Gislen, Kungl. Svenska Vet.-Akad. Handl., vol. 59, No. 4, 1919, p. 28 

 (comparison with milberti [=tessellala]). 



Diagnostic features. — A small species with the arms 70-95 mm. long and the 

 cirri XI-XVII, 25-35, 23 mm. long, with the longest segments about as long as broad. 

 The synarthrial tubercles are prominent, though broad and blunt. 



This species is closely related to A. ensijer from which it differs most obviously 

 in its broad and blunt, instead of produced, synarthrial tubercles. 



Description. — The centrodorsal is a thick convex disk, bearing marginal cirri. 



The cirri are XVII, 25-35. The segments are thick, the first five or six short and 

 broad and their immediate successors are about as long as broad. A faint dorsal 

 spine appears on about the tenth segment and increases in size rather rapidly, the 

 segments also shortening somewhat. In the later segments the spine is slightly 

 smaller and projects forward rather less strongly. The opposing spine is larger than 

 any of the preceding spines. 



The radials are visible and are longer at the sides than in the median line. The 

 IBr, are broadly hexagonal and are partly united laterally. The IBr 2 (axillaris) are 

 almost triangular and are but little longer than the IBr!. The elements of the IBr 

 series rise toward the middle of the articulation between them into an elevation which 

 stands up as a prominent tubercle. 



