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Show 410 PROF. F. JEFFREY BELL ON THE [May 1, concerned Ophiocrene seems to show that some ancestor of this group was provided with distinct radial shields, the presence or absence of which is so variable a character in the Streptophiurse, which I have, I think, shown to be ancestral to the Cladophiurae. OPHIOCRENE \ An Ophiuroid with branching arms and the habit of an Astro-phytid, but with calycinal plates on the disc, and rounded radial shields of comparatively small size. OPHIOCRENE ENIGMA, sp. nov. (Plate XXVII. figs. 1-5.) As there is only one specimen, and that small, it is impossible to say whether or no it is adult. It may be provisionally defined thus :-Small, with delicate arms and few branches, of a milky-white colour, the joints separated by fine brown lines. Macclesfield Bank, 45 fms. It may be pointed out that, at present, there is no evidence that would justify us in regarding this as the young of some already known Astrophytid of large size, but it is quite within the bounds of possibility that a series of stages may show it to be so. V. ECHINOIDEA. TEMNOPLEURUS BOTHRYOIDES. Pleurechinus bothryoides, A. Agass. Chall. Eep. Ech. iii. p. 108 (1881). Temnopleurus bothryoides, Bell, Eep. Voy. 'Alert' (1884) p. 119. It is quite clear that this is by no means a rare species ; the ' Challenger' and the ' Alert' both brought home examples, and the ' Egeria' took it in at least four dredgings between 40 and 47 fathoms. In the smallest specimen, which is not 4 mm. in diameter, the deep and extensive pitting characteristic of the species is quite well marked. I have a pretty strong conviction that the progress of research will result in showing that Pleurechinus variabilis and P. ruber Dr. Doderlein are synonyms of this variable species. TEMNOPLEURUS REYNAUDI. Temnopleurus reynaudi, Agass. An examination of two specimens covered with spines confirms me in the view I expressed in 18802 that T. reynaudi and T. granulosus are distinct species. The examples now before me are somewhat larger than the spined specimens collected by H.M.S. ' Challenger;' the spines are rather long, creamy white, with bands of red, or with the free end red. 1 As the word Egeria has been several times used in Zoology, and as Kpnvrj means a fountain, and Egeria was, it is said, changed into a fountain by Diana, I have, in this roundabout fashion, succeeded in associating H.M.S. 'Egeria' with this interesting genus. a P. Z. S. 1880, p. 424. |