14 A MONOGRAPH OF THE 



2. Ophlitaspongia, Bowerbank. 



When the " Tabular View of Systematic Arrangement ' 

 was published, in page 159, Vol. I, of this work, no sponge, 

 with which I am acquainted, having the structural pecu- 

 liarities of this genus, had been systematically named or 

 described. The spiculated fibres of one Australian and two 

 West Indian species were figured in Plate XVII, Figs. 288, 

 289, 290, and their structural peculiarities described in 

 pages 275, 276, as instances of the forms and positions 

 of internal defensive spicula. Since this period, in June, 

 1865, I have received a specimen of a species washed 

 ashore at Vazon Bay, Guernsey, and found with numerous 

 other well-known British sponges, by Mr. Cooper, of Rohais, 

 who presented the greater portion of the specimen to the 

 Rev. A. M. Norman, from whom I obtained it for descrip- 

 tion. It therefore becomes necessary that the genus should 

 be characterised, and added to the other British genera in 

 this synopsis, following that of Chalina in the third sub- 

 order of the order Keratosa, and I propose the following as 

 its characters. 



Ophlitaspongia, Bowerbank. 



Skeleton fibrous. Fibres keratose, solid, cylindrical, and 

 exterspiculate. Spicula based on the surface of the 

 fibre, and radiating thence at various angles, either 

 singly or in groups. Rete symmetrical. 



The type species 0. papilla is the only British species 

 with which I am acquainted ; but amongst the Australian 

 and West Indian sponges the species are, I believe, by no 

 means few in number. As far as they have yet been 

 examined, they appear all to harmonise with the generic 

 description of the British specimen, but the defensive 

 spicula with which, in all cases, they are profusely furnished 



