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Show 400 PROF. F. JEFFREY BELL ON THE [May 1, ment that the syzygial mode of union makes the arms more fragile at the points where it occurs, those who believe in the efficiency of Natural Selection will not accept the view that this doubling of the syzygies is of advantage to the possessor. I hope, therefore, that the peculiarities of this specimen (I will not say of this species) may come under the notice of those who work at Crinoids, and that material may be gathered sufficient for us to make up our minds as to whether we have to do with an individual eccentricity or a true character specifically distinctive of its possessor. There remain to be noticed five bidistichate species with more than ten arms of which I cannot give full descriptions, as the single specimens by which they are represented are not always well preserved. Diagnoses, however, are possible. They may be thus arranged, in accordance with Dr. H . Carpenter's scheme on pp. 211, 212 of the Eeport on the ' Challenger' Comatulae :- A. Over 30 cirrus-joints i. Antedon vicaria. B. 30 or less than 30 cirrus-joints. Cirri without definite arrangement. 25 cirri of 9 joints each ii. Antedon brevicirra, About 30 cirri of 16 smooth joints ... iii. Antedon flavojnaculata. sides to brachials Sides hardly flattened. Faint spinous process on later cirrus-joints iv. Antedon moorei. Very broad spinous process on later cirrus-joints v. Antedon fieldi. A N T E D O N YICARIA, sp. nov. Bidistichate, with wall-sided radials, strong pinnules, and about 30 cirrus-joints, of which the more distal are spiny. With so much resemblance to A. macronema, it has shorter cirri (20 mm.) and has numerous (30) joints. Arms probably about 25 in number. Neither radial nor distichal palmars syzygial. Cirri white, arms white with middle dorsal line of purple, pinnules purplish. Spread 100 mm.; diameter of deeply incised disc 4 m m . Macclesfield Bank, 30-40 fms. ANTEDON BREVICIRRA, sp. nov. Bidistichate, with flattened sides to brachials, 25 cirri of 9 joints, rather more than 40 arms, and a long first pinnule. Colour light brown. Macclesfield Bank, 20-35 fms. This species is so much broken that I should not have described it did I not wish to call attention to the short cirri set at the edge of the disc, recalling in every way the cirri of an Actinometra. ANTEDON FLAVOMACULATA, sp. nov. Bidistichate, with (in the single known specimen) exactly 20 arms; about 30 cirri, with 16 smooth joints, and the centre of the |
