Sponges Jrom the Atlantic Ocean. 4()1 



and grow on rocks or attached to stones, while this is only 

 partially the case with the Ilexactinellida. 



The four species of Lithistina above mentioned come re- 

 spectively from the neighbouring seas of the AVest Indies, 

 Madeira, the Azores, and the coast of Portugal. The type 

 specimen of Discodcrmia pohfdiscus in the l^ritish Museum 

 came from the island of 8t. Vincent, in the West Indies, that 

 of Corallistes Boicerhankii from Madeira, i\ved o'i Macandrewia 

 azorica from the Azores, and that of Azorica Pfeifferce from 

 Madeira ; while, as above stated, all four species have been 

 dredged up on board the ' Porcupine ' near Cape St. \'incent. 

 Bocage's specimen o( Discodcnnia poli/ disc us came from the 

 coast of Portugal ; and t^chmidt^s Corai I istes clavateUa = Mac- 

 andrewia azorica, and his C. typus= Corallistes Boioerhankiij 

 respectively from the Gulf of Florida. 



Several dead fragments of Corallistes Bowerhankii were 

 dredged up in 374 fathoms near Cape St. Vincent, during the 

 cruise of 1870 (Hoy. Soc. Proceed, no. 125). On the jar are 

 the numbers " 25, 75, 374 fathoms." I assume that '' 75 " 

 means from 75 to 374 fathoms ; otherwise I do not know what 

 it means ; the number of the station is of course " 25." They 

 are about 4 inches in diameter ; and the thickest piece is | of 

 an inch between the two surfaces. Although much worn, they 

 are still angular and undulating in shape, as if they had once 

 formed the walls of a sliallow goblet like tliat of the type 

 specimen in the British ^Museum ; but some fragments being 

 much thicker than any part of this specimen, they probably 

 belonged to a " goblet " of much larger dimensions. Having 

 been dead for a long time, they are of course sarcodeless, and 

 now more or less filled with deep-sea organisms {GlobigerinOy 

 «S:c.), besides being overgrown in many parts with a variety of 

 other sponges gathered during the time they have been drifting 

 about the bottom of the sea. There is little or no difference 

 in form between their flat surfaces ; and this is the case with 

 the type specimen mentioned, which was taken alive and there- 

 fore still possesses its dermal sarcode intact, so that there is not 

 much for identification left ; but in some parts of the fragments 

 where the mud has been washed out or had never entered, the 

 large and characteristic dermal S})icule, with its furcate arms, 

 is still present in considerable abundance, although not exactly 

 in situ ; for it appears among the other spicular structure of the 

 mass just below the surface ; the minute or flesh-spicule, how- 

 ever, is altogether gone, having floated off or out, probably 

 when the sarcode passed into dissolution. Still, the large 

 dermal sjiicule is sufficient, from its peculiar form and the 

 horizontality of its arms, together with its long shaft, to preclude 



