A MONOGRAPH OF THE EXISTING CRINOIDS 393 



sponding West Indian genera), p. 22 (distribution in detail; down to 35 fathoms; all the large 

 species confined to the Philippine Islands, the Moluccas, and the Solomons; represented in the 

 Atlantic by Analcidometra [in reality belongs to the Colobometridae]) , pp. 47, 51 (in keys), 

 p. 57 (key to the included genera); Journ. Washington Acad. Sci., vol. 4, 1914, pp. 559-563 

 (correlation of geographic and bathymetrical ranges), p. 582 (relation to temperature of habitat) ; 

 American Journ. Sci., vol. 40, 1915, p. 67 (detailed philosophical discussion of bathymetrical 

 range); Internat. Revue gesamt. Hydrobiol. und Hydrogr., 1915, p. 223 and fl. (detailed account 

 of the distribution in Australia); Unstalked crinoids of the Siboga-Exped., 1918, p. 93; Univ. 

 Iowa Stud. Nat. Hist., vol. 9, No. 5, 1921, p. 14 (not represented in the West Indies); Smith- 

 sonian Misc. Coll., vol. 72, No. 7, 1921, p. 3.— Gisl£n, Zool. Bidrag Uppsala, vol. 9, 1924 p. 

 10 (P 2 ), pp. 19, 42, 55, 78, 84, 89, 99, 231, 280, 287; Arkiv for Zoologi, vol. 19, No. 32, 1928, p. 6; 

 Kungl. Fysiogr. Sallsk. Handl., new ser., vol. 45, No. 11, 1934, pp. 20, 25; Kungl. Fysiogr. 

 Sallsk. Lund Forh., vol. 7, No. 1, 1936, p. 11. 



St^phanometres A. H. Clark, Bull. Mus. Hist. Nat., Paris, 1911, p. 252. 



Mariametres A. H. Clark, Bull. Mus. Hist. Nat., Paris, 1911, p. 253. 



Diagnosis. — A family of the superfamily Mariametrida in which the elements of 

 the IBr series are united by synarthry, and the arms are always more than 10 in num- 

 ber, the IIBr series being always 2. The perisome of the disk is most commonly naked, 

 but sometimes there are more or less conspicuous scattered thick plates or concre- 

 tions, which may be more or less contiguous, especially along the ambulacral grooves, 

 or the disk may be almost or quite completely plated (see Part 2, p. 228). The lateral 

 perisome of the pinnules usually contains simple, more rarely forked or multiradiate, 

 spicules, between which and the edge of the pinnulars there may be small straight 

 spicules or small rods; but calcareous deposits are frequently wholly absent (see Part 

 2, pp. 241 [Stephanometra] to 244). 



Geographical range. — Southern Japan from the Oki Islands in the Sea of Japan 

 to Tokyo Bay, the Bonin Islands, the Philippine, Pelew, Caroline, Marshall, and 

 Hawaiian Islands, Samoa, Fiji, the Tonga Islands, New Caledonia, northern Australia 

 south to Cape Hillsborough, Queensland, and the Abrolhos Islands and possibly 

 Perth, Western Australia, and the Lesser Sunda Islands, and westward to Madagascar 

 and the east coast of Africa from the Red Sea south to Durnford Point, Zululand. 



Bathymetrical range. — From the shore line down to 245 (?421) meters. 



Remarks. — The 27 forms included in the family Mariametridae fall into seven 

 genera — Oxymetra, Stephanometra, Pelometra, Liparometra, Lamprometra, Dichro- 

 metra, and Mariametra. 



The structural range within the Mariametridae is very small when compared 

 with that within the Zygometridae and Himerometridae, and especially within the 

 Colobometridae. 



The genus Oxymetra, with its long many-jointed cirri and characteristic lower 

 pinnules, is rather sharply separated from the other genera of the family, and bears a 

 considerable superficial resemblance to the genus Pontiometra of the Colobometridae. 

 The other six genera are all closely related, and young or immature individuals of the 

 included species are sometimes not easily determined generieally. 



The species of the genus Lamprometra is exceedingly variable in regard to the 

 proximal pinnules and the cirri, though these always keep within well-defined limits, 

 and there is never any difficulty in distinguishing it from species in other genera. 



208244 — 40 26 



