658 BULLETIN 82, UXITED STATES NATIONAL MUSEUM VOLUME 1 



The color of the first four or five cirrus segments v?as 3'cllo\v, the rest were dusky; 

 othenvise the specimen was light yellow. 



The marsupia are very large and extend fm-ther distally than the ovaries. The 

 transparent walls are often ruptured. The ovary lies a little to the adoral side of the 

 pinnule, with the marsupium mainly on the aboral side but extending distally across 

 the ventral side of the ovary onto the adoral side, so that it is comma-shaped. The 

 embryos are in various stages of development, but the most highly developed are 

 towards the distal end, which appears to be the most easily ruptured part. A large 

 marsupiiun has about 17 embryos, which are arranged in an iiTegular double layer and 

 are in various developmental stages. Since the most advanced are at the distal end, 

 it is presumed that the eggs pass from the ovary into the proximal part of the pouch. 

 The fulh' formed larvae are similar to, but larger than, those of the first specimen, being 

 0.30 to 6.36 mm. long. 



Some males also from station 1948 are larger, with the ossicles of the division 

 series and lower brachials relatively wider and more massive. The cirri are longer. 

 In two specimens P3 is the first genital, in the third it is P2. Pi has 19 to 20 segments, 

 and is 5 or 6 mm. long. 'When Po is genital it has 12 segments, 4 mm. long. The testes 

 are long fusiform bodies, the biggest lying along the third to eighth segments of the 

 genital pinnules. The disk is naked, the anal cone high. 



Localities. — Discovery Investigations station 156; off South Georgia (lat. 53°51' 

 S., long. 36°21' W.); 200-236 meters; rock; January 20, 1927 [John, 193S] (1, the 

 lectotype, B.M.). The type locality as now restricted. 



Discovery Investigations station 1948; east of Clarence Island (lat. 60°49' S., long. 

 52°40' W.); 490-610 meters; January 4, 1937 (4 syntypes, B.M.). 



Geographical range. — From South Georgia and the Bransfield Strait area. 



Bathymetrical range. — From 200 to 610 meters. 



PHRIXOMETRA EXIGUA (P. H. Carpenter)* 



Figure 37 



Antedon exigva P. H. Carpenter, Challenger Reports, Zoology, vol. 26, pt. 60, 1888, p. 178, pi. 32, figs. 

 1-4 (description; localities; affinities); Joiirn. Linn. Soc. (Zool.), vol. 24, 1891, p. 61 (intersj'zygial 

 interval). — Hartlaub, Bull. Miis. Comp. Zool., vol. 27, No. 4, 1895, p. 143 (range). — Grieg, 

 Bergons Mus. Aarb. for 1903, No. 5, 1904, p. 28 (intersyzygial interval). — Doderlein, Fauna 

 Arctica, vol. 4, Lief. 2, 1905, p. 405 (antarctic representative of the Tcnella group). — Hamaxx, 

 Bronn's Klassen und Ordnungen des Tier-Reichs, vol. 2, Abt. 3, 1907, p. 1579 (listed). — A. H. 

 Clark, Smithsonian Misc. Coll., vol. 50, pt. 3, 1907, p. 353 (listed) ; Crinoids of the Indian Ocean, 

 1912, p. 33 (of Carpenter, 1&88= Thatimatometra exigua); Unstalked Crinoids of the Siboga- 

 Exped., 1918, p. 246 (referable to Hathrometra). 



Thaumaiomelra exigua A. H. Clark, Proc. Biol. Soc. Washington, vol. 21, 1908, p. 128 (listed); Crin- 

 oids of the Indian Ocean, 1912, p. 33 ( = Antedon exigua), p. 246 (synonymy; localities); Smith- 

 sonian Misc. Coll., vol. 61, No. 15, 1913, p. 66 (published reference to specimens in the B.M.; 

 Challenger sta. 145). 



Ilalhrometra exigua A. H. Clark, Bull. Inst. Oc^anogr. Monaco, No. 285, 1914, p. 20 (closely related 

 to H. tenella; range); Journ. Washington Acad. Sci., vol. 5, No. 3, 1915, p. 81 (Antarctic; depth); 

 Die Crinoiden der Antarktis, 1915, p. 105 (collected by the Challenger), p. 107 (in key to Antarctic 

 crinoids), p. 144 (synonymy; localities; discussion), p. 168 (range), p. 169 (relationships). — Gisl^n, 

 Ark. Zool., vol. 15, No. 23, 1923, p. 16 (in key), p. 30 (range); vol. 19, No. 32, 1928, p. 11 (notes). 



Retiomelra exigua A. H. Clark, Proc. U. S. Nat. Mus., vol. 83, 1936, p. 248 (listed). 



* See also Addenda (p. 837) under 1963. 



