366 BULLETIN 82, UNITED STATES NATIONAL MUSEUM 



spinous distal ends. The pinnules on the outermost arms of each postradial series 

 appear to be considerably longer than those on the inner arms. 



Side- and covering-plates are very highly developed. 



The disk is unknown. 



Locality. — Investigator station 236a; northeast of North Andaman Island (lat. 

 14° 08' N., "long. 93°08'E.); 302 meters; April 11, 1898 [A.H.Clark, 1909, 1911, 1912, 

 1914, 1918, Gisl^n, 1922, 1934] (1, I. M.). 



History. — This species was described under the name Calometra spinosissima in 

 1909 from a single specimen dredged by the Royal Indian Marine Survey steamer 

 Investigator off the Andaman Islands in 1898. In 1911 the cirri were compared with 

 those of the new species Calometra alecto; but the name was misspelled spinossima. 

 In 1912 it was redescribed and figured under the name of Neometra spinosissima. 

 Its characters and affinities were discussed and the habitat given in 1914, and it was 

 included in a key to the species of the genus Neometra, with the range, in 1918. In 

 1922 and again in 1934 Prof. Torsten Gisl^n discussed various features of its structure. 



NEOMETRA CONAMINIS A. H. Qark 



Plate 36, Figure 191 



[See also vol. 1, pt. 2, fig. 838 (side- and covering-plates), p. 405.] 



Neometra conaminis Alexander, Rec. Western Australian Mus., vol. 1, pt. 3, 1914, p. 108 {nomen 

 nudum: between Fremantle and Geraldton). — A. H. Clark, Rec. Western Australian Mus., 

 vol. 1, pt. 3, I9I4, p. 115 (discovery; faunal affinities), p. 128 (systematic affinities), p. 129 

 (between Fremantle and Geraldton, 80-120 fms.; description of the type specimen; com- 

 parisons), p. 130 (characters; range); Internat. Rev. gesamt. Hydrobiol. und Hydrogr., 1915, 

 p. 225 and following (distribution); Unstalked crinoids of the Siboga-Exped., 1918, p. 133 (in 

 key; range). — Gisl^n, Kungl. Fysiogr. Sallsk. Handl., new ser., vol. 45, No. 11, 1934, p. 20. — ■ 

 H. L. Clark, Echinoderm fauna of Australia, 1946, p. 55 (notes). 



Diagnostic features. — The 20 arms are not over 90 mm. in length; the arms are 

 broader and more roimded dorsally than those of N. alecto, with the distal edges of 

 the brachials less produced; the curi are less than one-third of the arm length, stouter 

 than those of A^^. alecto, with 39-46 segments of which the distal edges are not modified ; 

 the first segment of Pi is not produced dorsally and is only slightly broader than the 

 second; and the first segment of P2 is without a dorsal process. 



Description. — The centrodorsal is of medium size, discoidal, with the flat dorsal 

 pole 4.5 mm. in diameter. The cirrus sockets are arranged in a single more or less 

 irregular marginal row, rarely with traces of a second 



The cirri are XIV-XIX, 40-45, 25 mm. long. The longer earher segments are 

 from half again as broad as long to nearly as long as broad, and the shorter distal 

 segments are about three times as broad as the median length, becoming longer again 

 terminally. On the sixth or seventh segment the median dorsal portion of the distal 

 edge becomes slightly prominent, this prominence gradually rising in height and slowly 

 extending itself proximally until on about the tenth there results a narrow median 

 keel rurming the whole length of the dorsal surface. On the succeeding segments this 

 gradually increases in height, becoming the high, thin, median carination character- 

 istic of the outer cirrus segments of all the species of this genus. The ventral surface 

 of the cu-ri is rather narrowly rounded so that in cross section the cirri are seen to 

 approach a rhombic shape, but with the four angles of the rhombic outline very broadly 



