Rhizaxinella nuda — Wilson 1925: 352 – 353, pl. 38 (fig. 5). Description External morphology. Small clubshaped sponges with rather damaged stalks (figs. 15 A – E). Their height varies from 0.6 to 2.1 cm. The surface is velvety, greyish. Consistency is rather soft. A contracted osculum is located slightly eccentrically on the top of main body. Skeleton. The choanosomal skeleton is constituted by the principal tylostyles arranged more or less radially and grouped in tracts or bundles (fig. 15 F). The ectosomal skeleton is formed by the bouquets of small tylostyles, densely packed and intermingled. Skeleton of the stalk not observed because of considerable damage of the latter. Spicules. Altogether 120 spicules from 2 specimens were measured. Two size categories are well distinguished. The number of measured spicules of each category is given below, separately for each specimen (n 1, n 2). Both principal and ectosomal spicules possess welldeveloped spherical tyles. Principal tylostyles are slightly fusiform and straight (fig. 15 G). Their dimensions are: length 1150 1759 2318 µm, tyle diameter 17 18.9 21 µm, diameter of the shaft underneath the tyle 13 14.3 15 µm, maximal diameter of the shaft 13 16.2 21 µm (n 1 = 30, n 2 = 30). Ectosomal tylostyles are isodiametric, straight or slightly curved (fig. 15 H). They measure: length 450 551 690 µm, tyle diameter 9 13.7 18 µm, diameter of the shaft underneath the tyle 7 9.0 11 µm, maximal diameter of the shaft 8 10.1 13 µm (n 1 = 30, n 2 = 30). Spicules of the stalk were not observed.
Sumber: Polymastiidae and Suberitidae (Porifera: Demospongiae: Hadromerida) of the deep Weddell Sea, Antarctic *