144 BRITISH SPONGES: 



they are;, flexible, tough, and the texture extremely fine. The 

 spiculae that support the fleshy part, appear to be the base or 

 continuation of the tubes ; perhaps these are ligaments, and may 

 contribute to give some small action to the tubes by inclining 

 them to either side, or by expansion and contraction. When 

 first separated from the rocks, the asbestine-like spiculae are not 

 so obvious as when the flesh is contracted by drying. In its 

 general appearance, this sponge bears some resemblance to 

 Lichen filifoi-mis. — The only specimen was taken by dredging, 

 and is an inch and a-half in length." 



The figure in Zoologia Danica is less characteristic than 

 Rathke's short description : " Hsemisphaerica erat cava e griseo 

 flavescens, lapidi innascens tubulis conico flexuosis in superficie 

 erainentibus, inaequalibus ; textura stuposa et fragilis est fibris 

 brevibus." 



" A flint stone, found on the shore at Dawlish in Devon- 

 shire, bears decided marks of having derived its form from the 

 siliceous impregnation of Sp. mammillaris." — Parkinsons 

 Oryctology, p. 51. 



33. H. ricus, bulbous, or pear-shaped, very compact, the 

 surface even and smooth ; oscida feio, scattered, closed when 

 dry, often obsolete : spicida needle-shaped. 



Plate XV. Fig. 4 and 3. 



Alcionio tuberoso in forma di'fico, Imperat. Ital. 641, fig. inf. 

 Sponge called the Sea- Fig. Ellis and Soland. Zooph. 206, pi. 59, 



fig. 4. 

 Alcyonium Ficus, Esper, Alcyon. tab. 20, fig. 1-4. 

 Akyonium ficiforme. Lam. Anim. s. Vert. ii. 394 : 2de edit. ii. 599. 



Hah. In deep water at Scarborough, rare, Mr Bean. " In 

 the summer of 1823, having procured many specimens of Den- 



