768 DR. J. S. BOWERBANK ON THE SPONGIAD.E. [Nov. 21, 



or less yellow in colour ; the arrangement of nervures much the same ; 

 palpi thicker, antennae much more slender. Type G. divisa. 



Celerena vulgaris, n. sp. 



Allied to C. perithea, of Cramer, from Amhoina, but with the trans- 

 verse golden-yellow band of primaries twice as wide, and the black- 

 brown border of secondaries only half as wide : expanse of wings 

 2 inches 4 lines. 



This is evidently a very common species. 



The above-named genus will include the following species : — C. 

 leme, Boisd.; C. divisa, Walker ; C. andamana, Felder; C, commutata, 

 Walker; C. mutata, Walker ; C. perithea, Cramer ; C. proximo, spret a, 

 and connexa of Walker ; and C. eucnemis of Felder. 



5. Contributions to a General History of the Spongiadce. 

 By J. S. Bowerbank, LL.D., F.R.S., &c.— Part VIII. 



[Received November S, 1870.] 



(Plates LXXVIII.-LXXXI.) 



The Sponges described in the present contribution to a general 

 history of the Spongiadae are rare and very remarkable species. 

 Three of them are, to the best of my knowledge, unique specimens ; 

 and the fourth, Chalina verticillata, elucidates in a singularly 

 striking manner the structure and history of a diluvial fossil sponge 

 enveloped in flint, which has for a long period been a mystery to 

 palaeontologists. 



Desmacidon plumosa, sp. nov. (Plate LXXVIII.) 



Sponge elongately fan-shaped, pedicellate ; pedicle long and stout, 

 snnroth, fan-shaped, expansion prominently hispid on both planes. 

 Oscula simple, dispersed, minute, and numerous. Pores inconspi- 

 cuous. Dermal membrane aspiculous. Skeleton reticulated, rete 

 irregular ; primary fibres stout and solid, radiating irregularly from 

 the discal end of the pedicle in the same plane ; secondary fibres 

 radiating from the primary ones at nearly right angles to the planes 

 of the sponge, short, slender, and delicately plumous. Spicula sub- 

 fusiform-acerate. 



Colour, in the dried state, fawn-yellow. 

 Hob. Sharks' Bay, Western Australia. 

 Examined in the dried state. 



I obtained this singular and interesting sponge among many others 

 from a dealer in specimens of natural history, who stated that it was 

 from Sharks' Bay, Western Australia, It is 15 inches in height, and 

 about 5 inches broad at near the middle of the fan-shaped expan- 

 sion. No portion of the basal attachment remains ; and the pedicle 

 in its present state slightly exceeds 1 inches in length. It is slightly 



