284 Rev. A^ M. Norman on the Architectural embiyo stage ; and the form of that incipient canal-system is remarkably like the chamber left in the semiseptate dome at the base of Hali'physema. I may add, when referring to Barrois, that at pi. xiii. fig. 15 he gives a capital illustration of pseudopodial action in the young of Orantia compressa — an additional witness to what I have stated in the earlier part of this paper, that the protrusion of pseudopodial processes in Haliphysema is no proof whatever that it is not a sponge. EXPLANATION OF PLATE XVL Fig. 1. Haliphysema cotifertiim, Norman, x 40. Fig. 2. Haliphysema conferUmi, Norman, a single individual separated from the group, X 150. Fig. 3. Technitella legumen, NoiTuan, x 40. Fig. 4. Technitella legumen, Norman, anterior portion, X 40. Fig. 5. Technitella melo, Norman, X 100. Fig. 6. Technitella melo, Norman, posterior portion, X 40. Fig. 7. Marsipella elo'ngata, Norman, X 100. XXXI. — On the Architectural Achievements of little MasonSj Annelidan (?) and Rhizopodan^ in the Ahyss of tJie At-lantic. By the Rev. A. M. Norman, M.A. No group of Tnvertebrata has received more important addi-tions through the recent dredgings in the North Atlantic than the Arenaceous Foraminifera. The mode of incorporation of extraneous material in the tests of these and of other Rhizo-poda, and also in the tubes of wdiat are presumed to be cases of minute Annelids, is not only marvellously beautiful, but appears also to be almost endlessly diversified. The power of selection evidenced is truly wonderful : from the same ground, and therefore from the midst of the same material for use, I have seen as many as seventeen different species, each of which has a specific individuality of its own in the choice and mode of appropriation of the particles, whether of mineral or organic origin, which it selects from the mud — and this wholly apart from characters which depend on the form of the one or more chambers which constitute the animal or tube. To exemplify my meaning I will throw the classes of diversity into tabular form, so as to give some slight idea of the varied ways in which these clever little artificers set about their work and_construct tlieir dwellings. A. Material chosen hy the Artificers. 1. Coarse sand-grains, almost entirely of quartz. 2. Medium-sized quartz-grains.
BioStor
