A MONOGRAPH OF THE EXISTING CRINOIDS 259 



paratively few cirri arranged in 10 definite columns; radial areas of the centrodorsal 



separated from each other by more or less developed ridges. . Aaterometridae (p 415) 



d . P, longer and stouter than P^, from slightly to very much longer and stouter; cirri never 



longer than the arms.. Thalassometridae (Bee Part 4c) 



c . Cirri usually short, stout, and strongly recurved, rarely more or less elongated, composed 

 of usually fewer than 25 segments of which the distal are little, if any, shorter than the 

 proximal and do not bear dorsal processes, though they may have a low blunt tubercle 

 at the distal end; all the segments uniform in color and surface texture; P, more slender 

 than the pinnules following and composed of shorter segments; Pj usually more nearly 

 like P, than like P, __, charitometridae (see Part 4c) 



Family TROPIOMETRIDAE A. H. Clark 



miberli group (part) P. H. Carpenter, Challenger Reports, Zoology, vol. 26, pt. 60, 1888 p 194 

 Tropiometndae A. H. Clark, Proc. Biol. Soc. Washington, vol. 21, 1908, p. 135 (includes Tropio- 

 melia, Asterometra, Calometra, and Plilometra) ; Proc. U. S. Nat. Mus., vol. 34, 1908, p. 210 

 (in key), p. 211 (includes Tropiometra, PtilomtlTa, Asterometra, and Calometra; range- not 

 represented in the Hawaiian Islands), p. 212 (range of component genera); Amer. Nat , vo'l 42 

 No 503, 1908, p. 722 (ecology); Geogr. Journ., vol. 32, No. 6, 1908, p. 602 (genera characteristic 

 of Indo-Pacific-Japanese region), p. 605 (ecology); Proc. U. S. Nat. Mus., vol. 36, 1909 p 361 

 (Antedon P. H. Carpenter, in part), p. 362 (perfected ambulacral plating onlv in this familv and 

 m the Thalassometridae), p. 365 (covering plates differ from those in Comatilia in being in 2 

 series instead of in one; side- and covering-plates extraordinarilv developed in Calometra, 

 more or less imperfect in Asterometra and Plilometra, and quite undeveloped in Tropiometra: 

 side- and covering-plates not found in young of Plilometra [in reality Aporometra]),p. 495 (com- 

 parison of ambulacral plating with that of West Indian species of the Fimbriata group of 

 Actmomelra [Nemasler]; Proc. Biol. Soc. Washington, vol. 22, 1909, p. 174 (referred to the 

 Comatulida Oligophreata) ; Vid. Medd. Naturh. Foren. K0benhavn, 1909, p. 133 (side- and 

 covering-plates), p. 152 (cirri compared with those of Zygomelra ftuctuans [= comala]); Proc. 

 U. S. Nat. Mus., vol. 40, 1911, p. 6 (3 species in African waters), p. 7 (species on west coast), 

 p. 8 (species on southeast coast), p. 9 (species on northeast coast), p. 649 (referred to the Oligo- 

 phreata) ; Die Fauna sudwest-Australiens, vol. 3, Lief. 13, 1911, p. 438 (1 genus and 2 species in 

 Australia); Mem. Australian Mus., vol. 4, 1911, p. 720 (proportion of the species of this family 

 in the Australian fauna), p. 727 (restricted to Tropiometra only), p. 729 (young diflfer widely 

 from adults; in key), p. 731 (one genus in Australia).— Hartlaub, Mem. Mus. Comp. Zool., 

 vol. 27, No. 4, 1912, p. 371.— A. H. Clark, Crinoids of the Indian Ocean, 1912, p. 6 (number of 

 genera in the East Indies; number also represented in the Atlantic; number represented in the 

 Atlantic by closely allied genera; number exclusively confined to the East Indies; number of 

 East Indian species), p. 11 (represented in the Ceylon region by Tropiometra), p. 12 (represented 

 in the Red Sea and southeast African regions by Tropiometra), p. 23 (distribution in detail; 

 doi\-n to 50 fathoms), p. 42 (revised so as to include Tropiometra only), pp. 46, 49 (in keys), 

 p. 58 (includes only the genus Tropiometra); Bull. Inst. Ocdanogr. Monaco, No. 294, 1914, pp. 7,' 

 8 (relation to temperature); Journ. Washington Acad. Sci., vol. 4, No. 19, 1914, pp. 559-563 

 (correlation of geographic and bathymetrical ranges) ; No. 20, p. 582 (relation to temperature of 

 habitat); Internat. Rev. gesamt. Hydrogr. und Hydrobiol., 1914, p. 4 and following (Tropio- 

 metra only genus; occurs in both Atlantic and Pacific; range); Rec. Western Australian Mus., 

 vol. 1, pt. 3, 1914, p. 114 (species collected by the Endeavour in Western Australia); Journ. 

 Washington Acad. Sci., vol. 5, No. 4, 1915, pp. 126-134 (phylogenetical and paleontological 

 significance of bathymetrical range); Die Crinoiden der Antarktis, 1915, p. 163 (represented in 

 South Africa by T. carinata); Amer. Journ. Sci., vol. 40, 1915, p. 67 (detailed discussion of the 

 significance of the bathymetrical range); Internat. Rev. gesamt. Hydrobiol. und Hydrogr., 

 1915, p. 225 and following (detailed account of the distribution of Australian species); Un- 

 stalked crinoids of the Siboga- Exped., 1918, p. vii (not found by the Albatross in the East Indies), 

 p. 131; Univ. Iowa Stud. Nat. Hist., vol. 9, No. 5, 1921, p. 12 (represented in the West Indies); 

 Smithsonian Misc. Coll., vol 72, 1921, No. 7, p. 3.— Gisl6n, Nova Acta Reg. Soc. Sci. Upsa- 



