4(J4 BULLETIN 82, UNITED STATES NATIONAL MUSEUM VOLUME 1 



in length. lu one of these P3 also has 14 segments but is 6.5 mm. long and in the 

 other it is 5.0 mm. long, with only 11 segments. A third specimen has no Pi complete 

 but P2 and P3 have 20 and 18 segments and measure 9 and 8 mm. respectively. I do 

 not agree with the original description which states that P3 is the longest proximal 

 pinnule. The distal pinnules have slender, simple, often somewhat bent spicules in 

 the tentacles. 



The color in alcohol is purphsh, tlic ventral side dark. 



Locality.— Sea Lark; off Providence Island, northeast of Madagascar; 228 meters; 

 J. Stanley Gardiner [A. H. Clark, 1911, 1913, 1918] (4, B.M.). 



PEROMETRA DIOMEDEAE (A. H. Cfark) 



FionRB 20 



[See also vol. 1, pt. 1, figs. 13 (p. 65) 112, (p. 179), 2S9 (p. 262), 387 (p. 307), 431 (p. 349), 503 

 (p. 371); pt. 2, figs. 82-84 (p. 53), 119 (p. 79), 319 (p. 227), 772 (p. 362)] 



Antedon diomedeae A. H. Clark, Proc. U.S. Nat. Mus., vol. 33, 1907, p. 132 (color), p. 146 (descrip- 

 tion; Albatross Sta. 4947); vol. 39, 1911, p. 562 (related to Aniedon pusilla P. H. Carpenter). 



Perometra diomedeae A. II. Clark, Smithsonian Misc. Coll., vol. 50, part 3, 1907, p. 358 (listed); 

 vol. 52, pt. 2, 1908, p. 230 (compared with P. elongate [Balanomelra balanoides]) ; Proc. Biol. 

 Soo. Washington, vol. 21, 1908, p. 225 (compared with Himerometra [Amphimetra] ensifer); 

 Proc. U.S. Nat. Mus., vol. 34, 1908, p. 275 (synarthri.al tubercles), p. 316 (localities in Sagami 

 Bay); vol. 35, 1908, p. 119 (arm structure; synarthrial tubercles) ; vol. 39, 1911, p. 502 (closely 

 related to /I ntoio«pusi7/o P. H. Carpenter) ; vol.40, 1911, p. 43 (compared with P.afra); Zool. Anz., 

 vol. 39, Nos. 11, 12, 1912, p. 423 (synarthrial tubercles compared with those of Calometra diana); 

 Crinoids of the Indian Ocean, 1912, p. 233 (synonymy; range); Smithsonian Misc. Coll., vol. 61, 

 No. 15, 1913, p. 58 (comparison with P. pusilla); Journ. Washington Acad. Sci., vol. 5, No. 6, 

 1915, p. 215 (southern Japanese species; range and its significance); Unstalked crinoids of the 

 Siboga-'Exped., 1918, p. 234 (in key; range; references).— GiSL:6>f, Zool. Bidrag Uppsala, vol. 9, 

 1924, p. 88; Vid. Medd. Nat. Foren. K0benhavn, vol. 83, 1927, p. 3 (Sta. 9) ; footnote 1 (includes 

 Erythrometra rubra part of Gisl(''n, 1922), p. 48 (notes), p. 68 (listed). 



Erythrometra rubra (part) GisLfiN, Nova Acta Reg. Soc. Sci. Upsaliensis, ser. 4, vol. 5, No. 6, 1922, 

 p. 140 (Sp. 1, 3; Bock Sta. 11; characters). 



Diagnostic features. — There are 10 arms only, which are up to 90 mm. long; P, is 

 usually absent; the synarthrial tubercles are extravagantly developed; there are 35 to 

 55 (usually about 40) cirrus segments.* 



Description. — The centrodorsal is small, usually rounded conical, but varying 

 from almost hemispherical (in small specimens) to long conical. The cirrus sockets 

 are closely crowded and more or less regularly arranged in 4 or 5 rows. The apex is 

 papillose. 



The cirri are XXX-XL, 35-55 (usually about 40), slender, 30 mm. long. The 

 first segment is short, the second is nearly as long as broad, the third is about as long 

 as broad, the fifth to eleventh are about twice as long as broad, and those following 

 become gradually shorter so that from about the eighteenth onward they arc about 

 as long as broad. On about the eighteenth segment the distal dorsal edge begins to 

 project, this condition passing gradually into low spines. In a lateral view the dorsal 



♦Utinomi and Kogo (see Addenda for 1965) identified as P. diortiedeae a specimen of which they 

 figured a cirrus ca. 30 mm. long with as many as 84 segments, all relatively shorter than those illus- 

 trated in figure 20. Since their specimen also appears to lack Pi as well as Po on the arm bases drawn, 

 it is possible that another species is involved. 



