A Monograph of the British Spongiadae Volume 4 (Paperback)

This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1882 edition. Excerpt: ...the skeleton is unmistakably that of an Isodictya. "There is but one form and size of the spicula in this sponge, the subfusiformi-acerate. A fully developed skeleton one measured-jq mcn m length and Hqqo inch in diameter. These dimensions are greatly in excess of those of the spicula of the greater number of species of Isodictya in this division of the genus. "In the dried state this sponge very closely resembles some of the varieties of Halichondria panicea in form, in colour, in the shape of the spicula, and in the possession of a reticulated dermal membrane, but the examination of a thin slice of the sponge at right angles to its surface immediately destroys the illusion; as the strongly produced scalariform structure of the genus Isodictya in this species is totally unlike the skeleton structure of a specimen of Halichondria panicea. "My friend the Rev. Mr. Norman states that this species 'was found at Westport Bay under stones at low-water spring tides August, 1875. This sponge is very easily recognised when living. It is of a lemonyellow colour, and runs irregularly over the stones in the form of large attached cloacal tubes, which here and there expand into outspread patches of the sponge from which arise several large upright cloacal openings. The sponge is very soft to the touch, the dermal membrane often much expanded with water, having a remarkable membranous appearance to the naked eye.'" 31. Isodictya Bowerbanki, Norman. Isodictya Simtjlo, Boiv., n, 279; in, PI. XLVIII, figs. 11--13. Habitat.--Filling the interstices of Nullipora polymorpha, and sometimes growing long enough to completely cover the Nullipore; dredged in Roundstone Bay, and under similar circumstances in Westport Bay (N.). "Among the...