A MONOGRAPH OF THE EXISTING CRINOIDS 13 



The edges are thickened, but smooth. There is a short spine at each angle. The 

 median keels of the first two brachials are lower than those on the preceding ossicles, and 

 the crest is smooth and straight. The first syzygial pair (composed of brachials 3+4) 

 is somewhat broader than long. The carinations on the hypozygal and epizygal are 

 not continuous, that on the epizygal being displaced outwardly. The next four seg- 

 ments are irregularly oblong, about three times as broad as the median length. Those 

 succeeding are very obliquely wedge-shaped, about twice as broad as the longer side, 

 terminally becoming less obliquely wedge-shaped and about as long as broad. The 

 arms are strongly compressed laterally, and the brachials are strongly carinate, the 

 carination being produced distally into a conspicuous curved overlapping spine. 



Syzygies occur between brachials 3+4, again from between brachials 29+30 to 

 between brachials 47+48 (usually between brachials 35+36, or near that point), and 

 distally at intervals of 5-7 (usually 6) muscular articulations. 



P, is 7 mm. long with 14-15 segments, moderately stout and tapering evenly to the 

 tip. The proximal outer side is strongly rounded. The ventral edges and the carinate 

 line on each segment are produced into high thin processes with a straight or more or 

 less convex crest. P 2 resembles Pj, and is nearly as long and large. P 3 is smaller and 

 shorter, and the pinnules following are shorter still. 



The color in alcohol is light brown, with the outer two-thirds of the cirri lighter. 



Comparisons. This species resembles S. diade.ma from southern Japan, but it is 

 larger and stouter with stouter cirri which have somewhat stouter segments; the carinate 

 processes on the division series are higher and more even, and there is a considerable 

 and conspicuous development of spines interradially on the division series and arm 

 bases. 



Parasite. A small parasitic gastropoid (tMelanella, sp.) was attached to one of the 

 cirri (see Part 2, pp. 645-649). 



Locality. Willebrord Snellius station 253*; north of western Ceram (lat. 251'00" 

 S., long. 1284S'00" E.) ; about 200 meters; April 28, 1930 [A. H. Clark, 1936] (1, L.M.). 



History. This species is known only from the single specimen dredged by the 

 Willebrord Snellius in 1930 and described in 1936. 



STENOMETRA QUINQUECOSTATA (P. H. Carpenter) 



PLATE 1, FIGURES 2, 3; PLATE 2, FIGURES 4, 6, 7 

 [See also vol. 1, pt. 1, figs. 9, p. 65, 269, p. 259, 485, p. 365; pt. 2, figs. 820-822, p. 392, pi. 2, figs. 979, 



980.] 

 Antedon quinquecostata P. H. CARPENTER, Challenger Reports, Zool. vol. 26, pt. 60, 1888, p. 215 



(description; Challenger station 192), pi. 3, fig. 6, a-d, pi. 38, figs. 1-3. HARTLAUB, Nova Acta 



Acad. German., vol. 58, No. 1, 1891, p. 77 (comparison with A. [Cosnriometra] conifera). HAMANN, 



Bronn's Klassen und Ordnungon des Tier-Reichs, vol. 2, Abt. 3, 1907, p. 1581 (listed). A. H. 



CLARK, Crinoids of the Indian Ocean, 1912, p. 34 (identity). HARTLAUB, Mem. Mus. Comp. 



Zool., vol. 27, No. 4, 1912, p. 309 (in Spinifera group; history), fig. 8, p. 364 (centrodorsal and 



radial articular faces). 



Thalassometra quinqueco&tata A. H. CLARK, Smithsonian Misc. Coll., vol. 50, pt. 3, 1907, p. 360 (listed). 

 Stenometra quinquecostata A. H. CLARK, Proc. Biol. Soc. Washington, vol. 22, 1909, p. 15 (listed); 



Vid. Medd. Naturh. Foren. K0benhavn, 1909, p. 186 (compared with S. dorsala [diadema]); 



Proc. U. S. Nat. Mus., vol. 39, 1911, p. 554 (compared with S. dorsata [diadema] and with S. 



cristata); Crinoids of the Indian Ocean, 1912, p. 34 (identity), p. 209 (synonymy; locality); 



Smithsonian Misc. Coll., vol. 61, No. 15, 1913, p. 44 (notes on three Challenger specimens in the 



British Museum); Unstalked crinoids of the Sifcoja-Exped., 1918, p. 156 (in key; range), p. 157 



