358 BULLETIN 82, UNITED STATES NATIONAL MUSEUM 



distal pinnules are very sharply triangular in cross section, 9 mm. long with 15 seg- 

 ments of which the terminal four or five, over which the ambulacral grooves do not 

 extend, abruptly smaller than those preceding. They resemble the distal pinnules of 

 the other species of the genus. 



The side- and covering-plates resemble those of N. alecto. 



Notes. Another specimen has 42 arms; there are two IVBr series, both developed 

 on the inner side of external IIIBr series ; the dorsal pole of the centrodorsal is from 6 

 to 7 mm. in diameter; the cirri are XXII, 44-46, from 35 to 40 mm. long; the color 

 is white, the outer portions of the arms narrowly banded, and the pinnules broadly 

 blotched, with purple. 



A third specimen has 41 arms about 75 mm. long; the cirri are XX, 39-44, from 

 35 to 40 mm. long. 



A fourth specimen has about 40 arms 65 mm. long; the cirri are about 30 mm. 

 long; the color is white, the arms beyond the division series narrowly and regularly 

 banded with purple, the bands being continued on to the pinnules. 



A fifth specimen has 40 arms 60 mm. long; the dorsal pole of the centrodorsal is 

 5 mm. in diameter; the cirri are XXI, 34-39, 25 mm. long. 



A sixth specimen has about 40 arms; there are two IVBr series. 



A seventh specimen has 40 arms and is similar to the preceding. 



Dr. Hubert Lyman Clark wrote in 1938 that he had before him one of the para- 

 types of tliis species, probably either the sixth or seventh specimen in the preceding 

 list. He said that all the arms are broken, but more than 36, and probably 40, were 

 present. There are two IVBr series. There are X cirri, all broken, and 13 sockets 

 on the margin of the large flat centrodorsal. 



Locality. Between Fremantle and Geraldton, Western Australia; 146-219 

 meters; Australian Fisheries Investigation steamer Endeavour [Alexander, 1914; 

 A. H. Clark, 1914, 1915, 1918; H. L. Clark, 1916, 1938; GislSn, 1934] (7, U.S.N.M., 

 35556; W. A. M.). 



History. This species was described in 1914 from seven dredged by the En- 

 deavour, and has not been reported since. In 1938 Dr. H. L. Clark published some 

 notes on one of the paratypes. 



NEOMETRA SIBOGAE A. H. Clark 



PLATE 38, FIGURES 197, 198 



Neometra sibogae A. H. CLARK, Zool. Anz., vol. 39, 1912, No. 11/12, p. 421 (description; Siboga 

 station 305); Rec. Western Australian Mus., vol. 1, pt. 3, 1914, p. 126 (comparison of postradial 

 series with those of N. gorgonia), p. 128 (specific relationships; peculiarities of distal cirrus seg- 

 ments), p. 130 (characters; range); Unstalked crinoids of the Siboga-'Exped., 1918, p. viii (a 

 new type discovered by the Siboga), p. 132 (in key; range), p. 135 (detailed description; station 

 305), p. 276 (listed), pi. 21, figs. 51, 52. GISLEN, Nova Acta Reg. Soc. Sci. Upsaliensis, ser. 4, 

 vol. 5, No. 6, 1922, p. 96 (characters of the lower pinnules); Kungl. Fysiogr. Sallsk. Handl., 

 new ser., vol. 45, No. 11, 1934, p. 25. 



Diagnostic features. The dorsal processes on the terminal cirrus segments are 

 triple as in N. gorgonia, but they differ from those in that species in being only 

 developed toward the tip of the cirri and also in consisting of a high median keel 

 flanked by a low ridge on either side; there are about 40 arms; the cirri are rather 

 slender, only about one-third of the arm length, with 31-36 segments; and the ossicles 



