Smithsonian miscellaneous collections . all three are from aworm-tube and mud bottom. It is of interest to recall that Craniella isone of the rather few sponges capable of living in or on mud. NO. 6 SPONGES OF THE ALASKAN ARCTIC—De LAUBENFELS 1/ The type is subspherical, about 4 cm. in diameter. The spirit speci-men has a similar shape, but is shghtly smaller (3 cm.). The other dryspecimen is elongate oval, 4 cm. in diameter, but 8 cm. high. Thecolor is the usual drab, the consistency cartilaginous. The surface of all three specimens is hairy on the lower half, or thedermis may be missing from
Smithsonian miscellaneous collections . all three are from aworm-tube and mud bottom. It is of interest to recall that Craniella isone of the rather few sponges capable of living in or on mud. NO. 6 SPONGES OF THE ALASKAN ARCTIC—De LAUBENFELS 1/ The type is subspherical, about 4 cm. in diameter. The spirit speci-men has a similar shape, but is shghtly smaller (3 cm.). The other dryspecimen is elongate oval, 4 cm. in diameter, but 8 cm. high. Thecolor is the usual drab, the consistency cartilaginous. The surface of all three specimens is hairy on the lower half, or thedermis may be missing from the lower half as a result of the dredgeimpact. The upper surface of each, especially the dry specimens, iscovered with conspicuous cone-shaped projections, much larger andmore acute than the structures (probably not homologous) that arecustomarily termed conules. These projections on craniana are 3mm. in diameter at the base, 6 to 8 mm. high, tapering steadily to atermination that is only slightly blunted. They are so crowded that. ^^t=^ Fig. 10.—Spicules of Craniella craniana. A, Cladome of anatriaene, X 150;B, cladome of prodiaene, X iSO; C, microscleres (sigmas), X 650. Camera lucidadrawing. their bases touch one another. Neither pores nor oscules show, doubt-less being closed during the dredge haul. The architecture is typical choristid, with huge fascicular columns,which arise from a point near the center of the base of the sponge, andcontinue clear to the surface. These are each about i mm. in diameter,and either touch one another, side by side, or (near the surface) havespaces of flesh between them as much as i mm. wide. The commonest megasclere is a large oxea, often over 100 micronsthick and several millimeters long. As usual in the order Choristida,the longest specimens were broken before they could be subjected tomicroscopic study, and there was great variation in size. There areanatriaenes, also of great variation. Some have clads about 200microns long and rha
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Keywords: ., bookauthorsm, bookcentury1800, bookdecade1860, booksubjectscience
