The primary gonad 68 8. The ectoderm ; larval nervous sj'stem 69 9. The shape of the larva; vibratile bands; vestibulum 70 10. The skeleton ' The specific name carinata adopted here is used on the authority of H. L. Clark, who mentions the species under this name in his report on the Echinoderms of Tobago. A. H. Clark, who formerly (On a collection of Crinoids from the Museum of Copenhagen, Vid. Medd. N. Foren. 1909, p. 182) held the same view, now (in The recent Crinoids of the coasts of Africa, Proc. U. S. Nat. Mus., 40, 1911) regards the Atl.intic species of Tropiometra as specifically distinct from the Tropiomelra carinata of the Indian Ocean, the Atlantic species being designated as T. picta (Gay) {brasiliensis Liitken). From a zoogeographic point of view I would expect them to be different species, but for want of sufficient material of the Indian form I have no opportunity for forming my own judgment in this case. Accordingly I have thought it my duty here to follow H. L. Clark in using the name carinata for the Atlantic form. ' H. L. Clark (Scientific Results of the Trawling Expedition of H. M. C. S. Thetis. Mem. Austral. Mus., IV, part ii, 1909) describes such specimens under the name of Himerometra pcsdophora, but A. H. Clark (The Recent Crinoids of Australia, Mem. Austral. Mus., iv, part 15, 1911, p. 785) maintains that they are Ptilometra mulleri.

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Diameter of disk, 10 mm. ; width of arms close to disk, 1.8 mm. ; length of arms, 35 mm. Five to six mouth papillae on each side of the mouth angle ; the outer one very small, the next one much larger than the others, rounded ; the three or four inner ones more or less conical, as is the one on the apex of the jaw. The teeth are pointed. than broad, with an angle wuthin and outer edge rounded ; lateral sides a little restricted throuo:h the i>:enital slits: the outer end is the widest. Side mouth shields short and rather wide, meeting within, almost equally broad in their wdiole length. First ventral plate very small, five-sided; those beyond a little longer than wide, in mutual contact almost, but not quite, to the end of the arm. Their inner end is truncated, their outer edge strongly curved, or with a rounded peak. Inner laterals re-enteringly curved, outer laterals restricted through the tentacle pores. Farther out on the arm, before they are sepa

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