SPONGE WEAVERS. 139 



survive the vicissitudes of thousands of years. The 

 most beautiful example of a sponge skeleton with 

 which we are acquainted are those elegant forms 

 which, at one time so rare, are now comparatively 

 common, called "Venus's Flower-basket," which is 

 the bare skeleton of a flinty sponge. The ordinary 

 size of one of these objects is from nine to ten 

 inches in length, and about one and a-half inches 

 in diameter at the top, curved and attenuated down- 

 wards, but with the upper two-thirds straight and 

 erect, resembling in shape the figures of a cornu- 

 copia. The entire fabric is cylindrical, and hollow, 

 looking like a delicate fairy-like basket-work, formed 

 of elongated fibres, which consist of bundles of long 

 thread-like spicules, crossed by similar bundles of 

 spicules at right angles, so as to leave nearly square 

 meshes, and these are crossed again at the angles, 

 leaving round openings, resembling the cane-work 

 of a cane-seated chair, but much finer, smaller, and 

 more delicate. The top is covered with a similar 

 network lid, composed of shorter spicules, and the 

 attenuated base is surrounded by a beard of long 

 filaments, like threads of glass, which have recurved 

 hooks towards the ends. Throughout its entire 

 length this fairy basket-work is ornamented still 

 further with oblique concentric ridges, or furbelows 

 of still more' delicate network, and a collar of like 

 material forms a fringe round the lid. As seen in 



