OCR Text |
Show 1881.] THE SURVEY OF H.M.S. 'ALERT.' 55 of calcareous substance, is button-like in shape, agrees in its ma-millation with the type specimen, but, instead of being white or grey, is dark brown, almost of the colour of C. fusca, Busk. It differs from the type in not showing the hood-like enlargements of the rostrum (possibly ocecia) which occur °at intervals in that specimen ; the rostra taper elegantly to a point, instead of being blunt; the spines, described as at the opposite side of the mouth, and which appear to be " spathulate " avicularian rostra, are present in much greater numbers here, and generally at the sides of the mouth-not at the opposite end to the rostrum. The surface of the cell is perforated by immense numbers of small punctures with regularity ; this is also the case in the type specimen, though not described or figured in loc. cit. As the original specimen has somewhat the appearance of having been partially bleached, its original colour very likely approximated to that of the specimen now described. Hab. Victoria Bank, off S.E. Brazil, 33 fathoms. CELLEPORA TURRITA, Smitt. Lepralia turrita, Smitt, Flo rid an Bryozoa, in K. Svensk. Akad. Handl. (n. s.) xi. p. 65, pi. xi. figs. 226-228. A single specimen, consisting of a stout cylindrical branch with incipient smaller branches, 17 millims. long by 5 in greatest breadth, stout, tapering to a blunt point. The number of distinct marginal tuberosities varies from two to four ; and they are unequal in size, one being generally of especial stoutness; and one, a mere inequality, bears a horizontal avicularium of some size; the large strong spathulate avicularia are numerous in the somewhat large spines between the zocecia, and occasional small sessile ones occur in the walls of the cells; the ovicells, which are numerous, bear small scattered punctures. This form differs somewhat from Smitt's specimens, chiefly in the ramose instead of sessile habit; the cells appear to be less crowded, and the number of spines less constant, while the marginal avicularium forms a constant character. Hab. Victoria Bank, off S.E. Brazil, 33 fathoms ; broken from larger colony. CELLEPORA DICHOTOMA, Hincks. Cellepora dichotoma, Hincks,Ann. N. H. ser. 3, ix. p. 305, pi. xii. figs. 7, 8. T w o specimens, respectively about \ and f inch high. The smaller is the more slender, and shows approximately dichotomous branching; the other is less regular. In the smaller one the margin of the mouth is well defined, though sometimes produced into a few points besides the low rostrum ; the avicularia are circular and slightly elevated. In the larger specimen the projections round the mouth are .onger, and the avicularia are sometimes spatulate. Hab. Victoria Bank, S.E. Brazil, 33 fathoms. |