A MONOGRAPH OF THE EXISTING CRINOIDS 461 



crinoids of the Siboga-Exped., 1918, p. 98 (in key; range), p. 103 (key to the included species).— 

 Gislen, Nova Acta Reg. Soc. Sci. Upsaliensis, ser. 4, vol. 5, No. 6, 1922, pp. 74, 76. — H. L. 

 Clark, Ann. South African Mus., vol. 13, pt. 7, 1923, p. 233 (questions desirability of recogniz- 

 ing the genus).— Gislen, Zool. Bidrag Uppsala, vol. 9, 1924, p. 84 (syzygies). 



Diagnosis.— A genus of Mariametridae in which P 2 and P 3 are elongated, slender, 

 of equal length, and similar except that P 3 has fewer segments than P 2 ; the division 

 series are in close lateral contact with straight and sharply flattened sides; the cirri 

 are rather short, with not more than 40 segments, of which few or none are longer than 

 broad and the distal are dorsally carinate or bear small dorsal spines, and the dorsal 

 surface of the division series is smooth, without ornamentation. 



Geographical range. — Southern Japan from Hirado Strait to Sagami Bay, the 

 Bonin Islands, and southward to the Tonga Islands, northeastern Australia (Port 

 Molle, Queensland), the Moluccas, and the Lesser Sunda Islands. 



Bathymetrical range. — From the shoreline down to 69 meters. 



Remarks. — The genus Liparometra as herein considered includes three species, 

 one of which, articulata, seems to be quite distinct, while the other two, regalis and 

 grandis, are very closely related and may eventually prove to be different forms of the 

 same species, or possibly even identical. All three seem to be rare. As we know them 

 at present their habitats are very widely separated, one occurring in southern Japan, 

 one in the Tonga Islands, and the third in the Australian region, extending to the 

 Moluccas and the Lesser Sunda Islands. But our information in regard to these 

 species is altogether too scanty to permit us to draw any far-reaching conclusions from 

 their apparently anomalous distribution. 



History. — The genus Liparometra was established by me in 1913, with the geno- 

 type Himerometra grandis A. H. Clark, 1908, to include M tiller's Comatula (Alecto) 

 articulata, Carpenter's Antedon regalis, and Himerometra grandis. These three species 

 had previously been included in the genus Dichrometra. 



KEY TO THE SPECIES IN THE GENUS LIPAROMETRA 



a 1 . Cirri long and rather slender, longest proximal segments from slightly longer than broad to one- 

 third again as long as broad, distal segments with prominent dorsal spines; P 2 and P 3 half again 

 as long as Pi, with 21-26 segments (Queensland to the Moluccas, Lesser Sunda Islands, and 



Armani; 0-69 meters) articulata (p. 461) 



a?. Cirri shorter and stout, longest proximal segments never longer than broad, distal segments 

 carinate dorsally or with slight dorsal processes; P 2 and P 3 twice as long as Pi, P 3 with 25-30 

 segments. 



b>. Less than 30 cirrus segments (Tonga Islands; littoral) regalis (p. 470) 



b 1 . More than 30 cirrus segments (southern Japan from Hirado Strait to Sagami Bay, and 

 Bonin Islands; 0-73 meters) grandis (p. 467) 



LIPAROMETRA ARTICULATA (J. Miiller) 



Plate 53. Figures 240-242 



Comatula (Alecto) articulata J. Muller, Abh. prcuss. Akad. Wiss., 1847 (1849), p. 263 (description; 



locality unknown). — A. H. Clark, Bull. Mus Hist. Nat., Paris, 1911, p. 245 (identity); Crinoids 



of the Indian Ocean, 1912, p. 30 (same). 

 Comatula articulata Dujardin and Hdpe, Histoire naturelle des zoophytes, fichinodermes, 1862, 



p. 207 (synonymy; description; no locality; Paris Mus.). 



