A MONOGRAPH OF THE EXISTING CRINOIDS 387 



synarthrial tubercles only very slightly developed. It appears to intergrade with 

 discoidea just as discoidea intergrades with tessellata. 



Localities.— Port Moresby, New Guinea [A. H. Clark, 1911, 1912, 1918] (1, 

 Austr. M.). 



Hood Lagoon, New Guinea [A. H. Clark, 1911, 1912, 1918] (11, U.S.N.M., 35244). 



Tonga and Fiji [A. H. Clark, 1912, 1913, 1918] (1, B. M.). 



Geographical range. — From Tonga and Fiji to southeastern New Guinea. 



Bathymetrical range. — Littoral. 



History.- — In a list of the localities at which Amphimetra discoidea has been found, 

 which I published in 1911, the specimens on the strength of which Port Moresby and 

 Hood Lagoon are included really represent this form. 



In my memoir on the crinoids of the Indian Ocean (1912) these two localities, 

 and in addition Tonga and Fiji, are given under Amphimetra schlegelii with which, 

 because of its slender cirri with long dorsal spines, this form was at the time supposed 

 to be synonymous. 



In a paper on the crinoids of the British Museum published in 1913 a specimen 

 labeled Tonga and Fiji was recorded under the name of Amphimetra papuensis. This 

 name here appeared for the first time, but the only characters given were those men- 

 tioned above under "Notes." 



In the Siboga report on the unstalked crinoids (1918) papuensis was included in 

 the key to the species of Amphimetra, and the synonymy and known localities were 

 given. 



AMPHIMETBA ENSIFER (A. H. Clark) 



Plate 38, Figures 172-174; Plate 39, Figure 179 



[See also vol. 1, pt. 1, fig. 86 (lateral view), p. 141; fig. 256 (centrodorsal), p. 255; fig. 337 (cirrus), 

 p. 285; fig. 474 (radial pentagon), p. 361; pt. 2, figs. 39, 40 (radial pentagon), p. 26.] 



Himerometra ensifer A. H. Clark, Proc. Biol. Soo. Washington, vol. 21, 1908, p. 225 (description; 

 Singapore). 



Amphimetra ensiformis A. H. Clark, Proc. Biol. Soc. Washington, vol. 22, 1909, p. 7 (listed; nomen 

 nudum). 



Amphimetra ensifer A. H. Clark, Vid. Medd. Naturh. Foren. K0benhavn, 1909, p. 158 (Singapore; 

 specimens described), p. 159 (compared with A. schlegelii), p. 193 (collected at Singapore by 

 Svend Gad); Smithsonian Misc. Coll., vol. 60, No. 10, 1912, p. 17 (compared with A. laevipinna) ; 

 Crinoids of the Indian Ocean, 1912, p. 113 (synonymy; Singapore); Unstalked crinoids of the 

 Siboga-Exped., 1918, p. 83 (in key; range), p. 8S (references; locality); Journ. Linn. Soc. (Zool.), 

 vol. 36, 1929, p. 640 (Singapore; 7 fathoms). — Gislen, Kungl. Fysiogr. Sallsk. Handl., new 

 ser., vol. 45, No. 11, 1934, p. 45. 



Diagnostic features. — A medium-sized or rather small form with the synarthrial 

 tubercles extravagantly developed and produced; the cirri are 23-30 mm. long, with 

 usually 30-35 segments of which the longest are usually slightly longer than broad; 

 the arms are 80-120 mm. long. 



Description. — The centrodorsal is thick discoidal. The cirrus sockets are arranged 

 in two closely crowded and irregular more or less alternating rows. 



The cirri are XV-XX, 30, from 20 to 25 mm. in length. The first segment is 

 very short, and those following gradually increase in length to the sixth, which is 

 about as long as broad. The next five or six segments are slightly longer than broad, 



