. Bulletin. Natural history; Natuurlijke historie. n L 50// Fig. 14.—Spicules of Erylus ministrongylus. A. Strongyles. B. Aspidasters. C. Centrotylote oxeas. D. Few-rayed oxyasters. E. Many-rayed oxyaster. A, B: scale I. C, D, E: scale II. YPM 5046. Holotype. Consistency. Very slightly compressible. Surface. The larger specimen has long broad folds and troughs. Much of its surface is riddled with small (inhalant?) openings less than mm in diameter. The sponge has one apical and two lateral oscules, each about 3 mm in diameter. The small openings are absent from some areas, including the re
. Bulletin. Natural history; Natuurlijke historie. n L 50// Fig. 14.—Spicules of Erylus ministrongylus. A. Strongyles. B. Aspidasters. C. Centrotylote oxeas. D. Few-rayed oxyasters. E. Many-rayed oxyaster. A, B: scale I. C, D, E: scale II. YPM 5046. Holotype. Consistency. Very slightly compressible. Surface. The larger specimen has long broad folds and troughs. Much of its surface is riddled with small (inhalant?) openings less than mm in diameter. The sponge has one apical and two lateral oscules, each about 3 mm in diameter. The small openings are absent from some areas, including the regions around the oscules and the tops of many folds. The incrusting specimen has small openings over the entire surface and no large oscules. Its surface is even. EcTOsoME. The cortex, 150-200 fi in thickness, can be detached in flakes. The cortical armor is built of many layers of tangentially placed disk spicules (aspidasters). Cen- trotylote oxeas form a sparse covering over the armor and a dense feltwork around die small surface openings. The uniporal openings lead to canals which are 40-200 fi in diameter. The canal linings contain numerous multi-rayed asters. Smaller numbers of oxeas and few-rayed asters are also present in the linings. Endosome. The interior is packed with two types of euasters. Centrotylote oxeas are common subcortically but become rare in the interior. Strongylote megascleres are scat- tered singly and also grouped into bundles which are 40-150 jx in diameter. Many bundles are radially or obliquely oriented. The triaenes are subcortical with their cladomes spreading under the cortex. A few aspidasters are present in the endosome. Spicules, (a) Orthotriaenes and dicho-orthotriaenes, with a short rhabd. The rhabds are 187-311 x 12-17 [x, and the clads 119-319 x 5-13 fx. In most spicules, rhabd length is slightly greater than clad length. A few spicules seen in section have clads longer than the radially placed rhabd. As examples, triaenes with unbroken
Size: 1390px × 1797px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookcollectionbiodiv, booksubjectnaturalhistory
