DTSIDEA. • 189 



" Dysidea fragilis. I received a specimen of this; 

 sponge from the Rev. A. M. Norman, presenting a very- 

 unusual aspect. It was a very thin stratum of irregu- 

 larly reticulated tissue, which, from the small shells and 

 other extraneous bodies adherent to the lower surface, 

 had evidently occupied a recumbent surface. Its 

 internal structure was also very singular. A few of 

 the larger fibres were well filled with sand, while by 

 far the greater number were entirely destitute of that 

 material. A similar paucity of sand may be frequently 

 observed in specimens from Brighton." 



Mr. Hyatt, in his * Revision of the North American 

 Poriferoe" pt. ii, 1877, has recorded what he believes 

 to be this Sponge from Zanzibar and also from 

 Biscayne Bay, Florida ; but his description and 

 photographic figures are not sufficient to enable us to 

 determine with certainty whether his Dysidea fragilis 

 is really our species or not; fig 17 does not so much 

 remind us of the facies of British specimens as does 

 the washed example represented in his fig. 18. 



Marshall* has published a valuable paper on th& 

 Sponges belonging to this family, but the British 

 species had not fallen under his observation. This 

 paper must, however, necessarily be referred to by 

 any one studying this genus. 



2. Dysidea coeiacea. Bow., hi, 341, PI. XCI, fig. 20. 



"A specimen was dredged by the Rev. A. M. Nor- 

 man in from five to six fathoms in Westport Bay, Co. 

 Mayo, Ireland. The sponge is two inches and a half 



* " UntersTicliungen liber Dysideiden und Phoriospongien," 'Zeit. 

 Wiss. Zool.,' XXXV, 1880, p. 88. 



