PART 6 A MONOGRAPH OF THE EXISTLNQ CRINOIDS 749 



with a species of Fariometra in the south and wnth a species of Retiometra in the north. 



History. — It is quite possible that the small form of Antedon from Vladivostock 

 mentioned bj- Prof, von Graff in 1884 as the host of an undetermined myzostome was 

 this species, as this is the only comatulid known from that region except for the very 

 much larger Ileliometra glacialis maxima. 



In a preliminary account (1907) of the comatulids secured bj^ the Albatross during 

 the cruise of 1906, I described as new Antedon tennis and Antedon ciliata. Subse- 

 quently coming across the name Antedon tenuis in one of Carpenter's papers, I proposed 

 the alternative name Antedon stella for my teiiuis later in the same year. But Car- 

 penter's Antedon tenuis is a nomen rrndum and is therefore without efToct so far as my 

 tenuis is concerned (A. H. Clark, 1908). 



In 1908, on proposing the new genus Thaumatometra with Antedon ciliata as the 

 type, I included in that species Antedon tenuis which seemed, on further study, to be 

 based on immature individuals of ciliata. The name tenuis was selected for the species, 

 however, because of page priority. In another paper published in the same year 

 I figured the centrodorsal and the base of one of the post-radial series. 



In 1909 I recorded Thaumatometra tenuis from 3 additional localities on the Korean 

 coast where it had been obtained by Suensson and Schonau, and in 1913 I added 

 another locality where it had been found by Suensson. 



In a memoir on the crinoids of the Okhotsk and Japan Seas published in 1937, 

 I gave the complete synonymy of this species and a number of new localities, together 

 with a complete list of the previous records and the geographical, bathymetrical, and 

 thermal ranges; also a general account of its associations. 



THAUMATOMETRA ABYSSORUM (P. H. Carpenter) 



Antedon abyssorum P. H. Carpenter, Quart. Journ. Micr. Sci., new ser., vol. 27, 1887, p. 386 {nomen 

 nudum; sacculi largely developed); Challenger Reports, Zoology, vol. 26, pt. 60, 1888, p. 190 

 (description; sta. 147), pi. 29, figs. 10-13. — Hartlaub, Nova Acta Acad. German., vol. 58, 

 No. 1, 1891, p. 14 (deep sea; 1,600 fms.). — Shipley, Antarctic manual, 1901, ch. 18, p. 269. — 

 DOderlein, Fauna Arctica, vol. 4, Lief. 2, 1905, p. 405 (antarctic representative of the TencUa 

 group). — A. H. Clark, Smithsonian Misc. Coll., vol. 50, pt. 3, 1907, p. 353 (listed). — Hamann, 

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

 Clare, Crinoids of the Indian Ocean, 1912, p. 33 (of P. H. Carpenter, 188S= TTiaumatometra 

 abyssorum). 



Thaumatometra abyssorum .\. II. Clark, Proc. Biol. Soc. Washington, vol. 21, 1908, p. 128 Oisted); 

 Crinoids of the Indian Ocean, 1912, p. 33 {^Antedon abyssorum P. H. Carpenter, 1888), p. 246 

 (synonymy; locality); Smithsonian Misc. Coll., vol. 61, Xo. 15, 1913, p. 65 (published references 

 to specimens in the B.M.; Challenger stA. 147; comparison with T. tenuis); Journ. Washington 

 Acad. Sci., vol. 5, 1915, No. 3, p. 81 (antarctic; range); Die Crinoiden der Antarktis, 1915, p. 106 

 (collected by the Challenger; recorded as Antedon abyssorum), p. 107 (in key to ant.irctic crinoids), 

 p. 147 (synonymy; locality), p. 170 (deep water antarctic species; occurs in the region south of the 

 Indian Ocean), p. 171 (systematic and geographical relationships); Unstalked crinoids of the 

 5i6offa-Exped., 1918, p. 255 (in key; range), p. 256 (references). — GiSLfis, Ark. Zool., vol. 19, 

 No. 32, 1928, p. 11 (centrodorsal). 



Diagnostic features. — There are 15 to 18 cirrus segments which are subcqual, 

 much elongated, the antepenultimate being about three times as long as its proximal 

 widtli and the peimltimate twice as long as wide; Pi and Pj have about 10 segments; 

 Pj bears a gonad. Wicn the arms are about 35 mm. long the longest cirri are at least 

 12 mm. 



