BRITISH SPONGIADjE. 35 



3. Grantia ensata, Bowerbank. 



Sponge. Elongately oval, sessile; surface smooth, fur- 

 nished abundantly with large fusiformi-acerate spicula, 

 disposed in lines parallel to the long axis of the sponge. 

 Cloaca central, cylindrical, nearly as long as the 

 sponge, armed internally with spiculated, equiangular, 

 triradiate spicula ; spicular ray ensiform, very long ; 

 mouth of cloaca simple, unarmed. Oscula simple, 

 slightly depressed, as numerous as the interstitial 

 cells. Pores inconspicuous. Skeleton spicula equi- 

 angular triradiate. 



Colour. — Cream white. 



Habitat. — Guernsey, Mrs. Buckland. 



Examined. — In the dried state. 



I am indebted to my kind friend the late Mrs. Buckland for 

 this new and interesting species. She found it at Guernsey, 

 between high- and low-water marks, parasitical on Corallina 

 officinalis. It is in size, form, and colour, so much like 

 Grantia ciliata that a superficial observer would very pro- 

 bably mistake it for that species. Of four specimens in my 

 possession, the largest is seven lines in length and two lines 

 at its greatest diameter, the smallest is three lines in length 

 and not quite two in diameter. All the specimens are sessile, 

 the base of the sponge embracing the stem of the Coral- 

 Una firmly. The defensive spicular rays arming the infe- 

 rior of the cloaca are remarkably long ; the ray progres- 

 sively increases in size from its insertion at the centre of 

 the triradiate .spiculum for about three fourths of its 

 length, and then gradually attenuates to its distal extre- 

 mity, where it terminates acutely, so that its outline is very 

 like that of an ancient sword. 



They are all of them more or less incHned towards the 

 mouth of the cloaca, and their abundance and efficiency 



