A MONOGRAPH OF THE EXISTING CRINOIDS 367 



rounded. The cirri taper slowly and gradually throughout their whole length and are 

 not particularly stout. 



The radials are concealed in the median line but extend upward in the inter- 

 radial angles of the cah'.x in the form of triangular processes of which the sides, which 

 are ahout as long as the base, are concave and the apices are truncated, entirely, 

 though not very widely, separating the bases of the IBr,. The IBri are very slightly 

 trapezoidal, almost oblong, from three to four times as broad as long; the ventro- 

 lateral edges, though sharp, are only very slightly, if at all, produced. These ossicles 

 occasionally bear an obscure low median keel. The IBr2 (axillaries) are broadly pentag- 

 onal, slightly broader than long, ^vith the lateral edges usually slightly shorter than 

 those of the IBrj. The IIBr series are 2. 



The 20 arms are from 85 to 90 mm. long and resemble those of the other species of 

 the genus. 



Pi is 9 mm. long with 25-30 segments of which the first two are greatly enlarged 

 and the remainder are slightly longer than broad. P2 is 12 mm. long with 16-17 

 segments which after the third become much elongated, those in the outer part of the 

 pinnule having produced distal edges bearing prominent spines at the prismatic angles; 

 the pinnule is stiff and spinelike. P3 is 15-17 mm. long with 16-18 segments and 

 resembles P2 but is proportionately larger. P, is 17 mm. long with 18 segments and is 

 similar to P3. P5 is 12 mm. long with 15 segments and is similar to the pinnules 

 preceding. Pj is 10 mm. long with 14 segments. The distal pinnules are about 

 1 1 mm. long. 



The side- and covering-plates do not differ essentially from those of N. alecto. 



Locality. — Between Frcmantle and Geraldton, Western AustraUa; 146-219 

 meters; Australian Federal Fisheries Investigation steamer Endeavour [Alexander, 

 1914; A. H. Clark, 1914, 1915, 1918; Gisl^n, 1934] (4, U.S.N.M., 35559; W. A. M.)- 



History. — Tliis species was described in 1914 from four specimens dredged by the 

 Endeavour off Western Austraha. Its distribution was given in 1915, and in 1918 it 

 was included in a key to the species of Neometra, with the habitat. Prof. Torsten 

 Gisl6n in 1934 discussed its type of arms branching. 



NEOMETRA ALECTO (A. H. Clark) 



(See vol. 1, pt. 2, figs. 835-837 (side- and covering-plates), p. 405.] 



Calomelra alecto A. H. Clark, Proc. U. S. Nat. Mus., vol. 39, 1911, p. 544 (description; Aibaiross 

 stations 5414, 5356, 5413; affinities). 



Neometra alecto A. H. Clark, Crinoids of the Indian Ocean, 1912, p. 184 (synonymy; locality); 

 Rec. Western Australian Mus., vol. 1, pt. 3, 1914,[p. 128, faffinities), p. 130 (characters; range); 

 Unstalked crinoids of the Siboga-Ex^ed., 1918, p. 133 (in key; range), p. 137 (notes; station 

 305), p. 276 (listed). — Gisl^n, Nova Acta Reg. Soc. Sci. Upsaliensis, ser. 4, vol. 5, No. 6, 1922, 

 p. 96 (characters of the lower pinnules).^A. H. Clark, Journ. Linn. Soc. (Zool.), vol. 36, No. 

 249, 1929, p. 646 (Rotti Strait; 100 fathoms). — Gisl^n, Kungl. Fysiogr. Sallsk. Handl., new 

 ser, vol. 45, No. 11, 1934, p. 20.— A. H. Clark, Proc. Biol. Soc. Washington, vol. 47, p. 11, 

 1934 (cast of Hainan). 



Diagnostic features. — In this species the 15-20 very narrow arms are from 60 mm. 

 to'70 mm. in length,^and have the distal ends'of^the'brachials rather strongly produced; 

 the cirri are rather slender, more than one-third of the arm length, composed of 39-46 

 segments of which the distal ends are prominent ; the first segment of Pi bears a high 



