18/3.] DR. J.S. BOWERBANK ON CEYLONESE SPONGES. 25 



Fig. 10. One of the small slender acerate spicula of the dermal membrane, mag- 

 nified 123 linear. 



Fig. 11. One of the small skeleton-spicula intermingled with the slender acerate 

 spicula of the dermal membrane, magnified 123 linear. 



Fig. 12. A full-sized skeleton -spieulum, magnified 123 linear. 



2. Report on a Collection of Sponges found at Ceylon by 

 E. W. H. Holdsworth, Esq. By J. S. Boyverbank, 

 F.R.S., F.Z.S., fee. 



(Plates V.-VII.) . 



[Eeceived November 6, 1872.] 



On the return of Mr. Hoklsworth from Ceylon, in 1871, he brought 

 with him a small collection of Sponges which he obtained at the 

 Pearl-banks and from the beach near his house at Aripo, on the 

 north-west side of the island. The total number is 25 specimens ; 

 many of those from the beach were in a condition in which specimens 

 thus obtained are usually found, either well-washed skeletons, or so 

 much deteriorated as to have destroyed a considerable portion of 

 their softer parts, on which their specific characters frequently de- 

 pend. I examined the whole of the specimens ; and the following is 

 a list of the genera and the number of species of each : — Chalina 1 1 

 specimens, consisting of 7 species ; Spongia 6 specimens, of 3 species ; 

 Stematumenia 2 specimens, of 1 species ; Dysidea 2 specimens, of dif- 

 ferent species ; and 1 species each of the following genera, Halt- 

 chondria, Desmacidon, Isodictya, Spongionella, and Haliphysema. 

 The last three of these species and one Dysidea are not only in a 

 fine state of preservation, but they also possess more than the usual 

 degree of interest from the singularities and beauties of their struc- 

 tural peculiarities, as well as from having been hitherto unknown to 

 science ; and I have therefore selected these species for description 

 and illustration. 



Spongionella Holdsworthii, Bowerbank. (Plate V.) 



Sponge cup-shaped, margin entire or lobed ; parietes very thin ; 

 pedestal short and stout ; surface smooth and even. Oscula simple, 

 rather equally dispersed ; orifices circular, or more or less radiating ; 

 pores inconspicuous. Dermal membrane thin and pellucid. Ske- 

 leton — primary lines regular, comparatively stout ; secondary lines 

 rather irregular, slender. 



Colour in the living state dark brown, like dirty leather (Mr. 

 Holdswertk). 



Hab. Nine-fathom line, or western margin of the great Pearl- 

 bank off Aripo, Ceylon (Mr. Holdsworth). 



Examined in the dried state. 



I received five specimens of this interesting species of sponge for 

 examination from my friend Mr. Holdsworth. They were all of 

 nearly the same size as the one represented by figs. 1 & 2, Plate V. 



