434 BULLETIN 82, UNITED STATES NATIONAL MUSEUM 



c?. Keels on the elements of the division series and first two brachials low, often reduced to a 



narrow slightly raised line (southwestern Japan; 162-188 meters).. macropoda (p. 441) 



6^. IBri with a slightly elongated sharp median tubercle or a short median ridge; axillaries with 



three tubercles; first two brachials each with a prominent sharp tubercle (Kei Islands; 



90-256 meters) longicirra (p. 439) 



a'. Elements of the division series and first two brachials smoothly convex dorsally (from the Bonin 

 Islands, southwestern Japan, and Formosa southward to the Sahul Bank; 64-185 [?210] 

 meters) an thus (p. 444) 



ASTEROMETRA MIRIFICA A. H. Oark 



Plate 40, Figure 208; Plate 42, Figure 216 



[See also vol. 1, pt. 1, figs. 43, o, 6 (lateral view of the centrodorsal and arm bases), 44 (ventral view 

 of the arm bases), p. 77; pt. 2, fig. 206 (lateral view), p. 143; fig. 207 (lateral view), p. 145.] 



Antedon longicirra (part) Bell, Journ. Linn. Soc. (ZooL), vol. 24,1893, p. 339 (Sahul Bank). — H. L. 

 Clark, Echinoderm fauna of Australia, 1946, p. 56. 



Aslerometra mirifica A. H. Clark, Proc. Biol. Soc. Washington, vol. 22, 1909, p. 146 (description; 

 Sahul Bank); Proc. U. S. Nat. Mus., vol. 39, 1911, p. 547 (comparison with A. cristata); Mem. 

 Australian Mus., vol. 4, 1911, p. 794 (synonymy; locality); Crinoids of the Indian Ocean, 1912, 

 p. 190 (synonymy; description; Sahul Bank); fig. 33, p. 192; Smithsonian Misc. Coll., vol. 61, 

 No. 15, 1913, p. 43 (published references to specimens in the B. M.; Sahul Bank; comparison 

 with A. longicirra); Unstalked crinoids of the Sihoga-'ExpaA., 1918, p. 141 (in key; range; 

 synonymy; notes; stations 260, 294), p. 275 (listed); Journ. Linn. Soc. (ZooL), vol. 36, No. 249, 

 April 1929, p. 647 (Rotti Strait; 100 fathoms). — Sieverts, Neues Jahrb. Min., Geol. und 

 Pal., vol. 69, Beilage-Band, Abt. B, 1932, p. 151.— Gisl^n, Ark. ZooL, vol. 26A, No. 16, 1933, 

 fig. 11, p. 8 (from A. H. Clark, 1921).— A. H. Clark, Treubia, vol. 14, livr. 2, 1933, p. 207 

 (listed), p. 213 (St. Nicolaas Bay; notes). — H. L. Clark, Echinoderm fauna of Australia, 1946, 

 p. 57 (Sahul Bank). 



Diagnostic features. — The elements of the division series and first two brachials 

 have a high thin median carination the crest of which is strongly convex in lateral 

 view so that the lower portion of the animal appears scalloped; 10-15 arms 80-100 

 mm. long; cirri IX-XIV, 78-108 (usually 90-100), 80-100 mm. long— about as long 

 as the arms. 



Description. — Although in general smiilar to A. cristata and to A. longicirra this 

 species may be readily distmguished from them by the very high sharp median keels 

 on the elements of the division series and on the first two brachials; these keels are 

 strongly convex in profile so that the outline of the lower portion of the animal con- 

 sists of a series of convex scallops instead of a straight line as in A. cristata or well- 

 spaced angular tubercles as in A. longicirra. 



Arms 10-15 in number. 



Notes. — Of the three specimens from Siboga station 260 two are very small and 

 one is nearly of full size. The last resembles very closely the type specimen from 

 the Sahul Bank. The arms are 70 mm. long; the cirri, which are composed of 87-89 

 segments, are 70-75 mm. long. 



Of the 11 speciments from the Danish Expedition to the Kei Islands station 24 

 three have 10, two 12, two 13, one 14, and three 15 arms. 



In one of the specimens with 12 arms the centrodorsal is columnar at the base 

 with the dorsal pole conical, the sides making an angle of somewhat more than 60° 

 with each other. The cirrus sockets are arranged in 10 crowded columns, the sockets 

 in adjacent columns alternating in position; there are one or two sockets to a column. 



