410 BULLETIN 82, UNITED STATES NATIONAL MUSEUM 



Stephanometra coronata A. H. CLARK, Proc. U. S. Nat. Mus., vol. 36, 1909, p. 639 (description; 

 "India"); vol. 39, 1911, p. 541 (Port Busin, Barias Island; "India"); Smithsonian Misc. Coll., 

 vol. 60, No. 10, 1912, p. 19 (synonym of echinus); Crinoids of the Indian Ocean, 1912, p. 133 

 (synonymy; detailed description; localities), fig. 13, a, b, p. 133; Unstalked crinoids of the 

 Siboga Exped., 1918, p. 93, footnote ' (synonym of echinus). 



Slephanometra echinus A. H. CLARK, Proc. Biol. Soc. Washington, vol. 22, 1909, p. 10 (listed); 

 Smithsonian Misc. Coll., vol. 60, No. 10, 1912, p. 19 (includes S. coronata; no locality; fragments) ; 

 Crinoids of the Indian Ocean, 1912, p. 132 (synonymy; locality); Unstalked crinoids of the 

 /S'6oga-Exped., 1918, p. 93 (in key; range), p. 94 (synonymy; notes; stations 40, 99), pp. 271, 

 272 (listed); Smithsonian Misc. Coll., vol. 72, No. 7, 1921, pi. 15, fig. 52 (arm). GISL^N, 

 Kungl. Fysiogr. Sallsk. Handl., new ser., vol. 45, No. 11, 1934, p. 25. GISLN, Kungl. Fysiogr. 

 Sallsk. Lund Forh. vol. 7, No. 1, 1936, p. 4 (French Indochina), p. 5 (range), p. 11 (Pulo 

 Condor; notes), figs. 2, 2a, p. 9. 



Diagnostic features. The outer cirrus segments have long, sharp, and prominent 

 dorsal spines; there are 30-40 (usually 30-35) arms 110-170 mm. long; and the cirri 

 have 25-37 segments. 



Description. The centrodorsal is discoidal, with the moderately large bare polar 

 area slightly concave ; the cirri are arranged in two closely crowded more or less alter- 

 nating rows. 



The cirri are XXIV, 26-30, 25 mm. long. The first four segments are about 

 twice as broad as long, the sixth is about as long as broad, and the seventh-tenth or 

 -eleventh are about one- third again as long as broad; the segments succeeding are 

 again about as long as broad, and those following gradually become shorter so that 

 the terminal 12 or 14 are broader than long. The tenth and following segments 

 bear large dorsal spines. The opposing spine is terminally situated, erect, and reaches 

 about one-half the width of the penultimate segment in height. The terminal claw 

 is rather longer than the penultimate segment and is slender and moderately curved. 



The radials project slightly beyond the run of the centrodorsal. The IBrj are 

 proximally about four and distally about three times as broad as long ; they are united 

 in their basal third, but their sides diverge very rapidly from the point of union so 

 that the free lateral borders of two adjacent IBr! form together an even and mod- 

 erately curved line. The IBr 2 (axillaries) are broadly pentagonal, nearly twice as 

 broad as long, with large and broad ventrolateral projections. The IIBr, IIIBr, and 

 IVBr series are 2, bearing on the outer side, in common with the first brachials, large 

 and broad ventrolateral processes. 



The 40 arms are 110 mm. long. One of the internal IIIBr series is missing, but 

 its loss is compensated by the development of an external IVBr series on the same 

 IIBr series. The first 9 or 10 brachials are oblong or very slightly wedge-shaped, 

 about twice as broad as long, those following becoming short-triangular, rather more 

 than twice as broad as long, and short-wedge-shaped in the distal portion of the arms. 



Syzygies occur between brachials 3+4, again from between brachials 22 + 23 to 

 between brachials 32+33 (most frequently in the vicinity of the twenty-third bra- 

 chial), and distally at intervals of from 9 to 24 (usually 9-13) muscular articulations. 



PI is large, stiff, and spinelike, resembling P 2 , with 15 segments and reaching 

 15 mm. in length. The first two segments are nearly twice as broad as long, the 

 third is about as long as broad, and those succeeding increase hi length so that the 

 seventh and following are from one and one-half tunes to nearly twice as long as 

 broad. P 2 is 16 mm. long with 12 or 13 segments, of which the distal are rather 



