THE ANNALS 



AND 



MAGAZINE OF NATURAL HISTORY, 



No. 99. MAY 1845. 



XLI. — Descinption of a new genus of Calcareous Sponge. By 

 J. S. BOWERBANK, F.R.S., L.S. &c. 



[With a Plate.] 

 DUNSTERVILLIA. 



Gen. Char. — Sponge calcareous, outer surface arranged in poly- 

 gonal plates or compartments. Body composed of simple, straight, 

 angulated canals radiating from the central axis of the sponge. 



D. elegans. — Sponge sessile, sacculate, compressed; ventral ori- 

 fice single, terminal, surrounded by a single or double fringe 

 of erect, simple, asbestiform spicula. External oscula indi- 

 stinct. Spicula of the body simple- double-pointed and tri- 

 radiate. 



This interesting little sponge was attached to the stem of a 

 new species of Coj^allina, which I received among a valuable col- 

 lection of Sponges, Zoophytes and Fuci from my kind and libe- 

 ral friend Mr. George Dunsterville, surgeon of Port Elizabeth, Al- 

 goa Bay, after whom I have named it in acknowledgement of the 

 repeated contributions which he has made to our knowledge of 

 the marine natural history of that part of the world. It was 

 found on the beach at Cape Receif, about ten miles from the 

 town. 



This singular sponge would naturally fall under Dr. Fleming's 

 Grantia, if we were to confine ourselves to the brief description 

 which he has given of that genus ; and even under the enlarged 

 generic character given by Dr. Johnston in his ^ History of the 

 British Sponges,' there is but a very slight distinction between 

 them. But however well the material may accord with that of 

 Grantia, the structural peculiarities are so strikingly distinct from 

 any species of that genus with which I am acquainted, that I 

 have ventured to make it the type of a new family ; and I have 

 been the more inclined to do so, as, although I know of no recent 

 analogue, yet there is one in the fossil state which is found in 



Ann. ^ Mag. N. Hist. Vol. xv. Y 



