352 ADDITIONS, 



Halichondria glabra. 



— Pattersoni. 

 Baphiodesma sordida. 



— lingua. 

 Isodictya densa. 



— Hyndmani. 



— indistincta. 

 Demacldon cojnosa. 

 Clialina Flemingii. 



— inornata. 



BOIONEMIA PONDEEOSA, Plate VIII. 



I received among other specimens from the Diamond 

 trawling ground off Hastings, a very fine specimen of 

 this sponge. It is rather larger than the figured one, 

 and it closely resembles it in form, exhibiting the 

 same disposition to divide into two large lobular 

 masses. The anatomical structures are in perfect 

 accordance with those of the type-specimen. There 

 are no indications of a basal attachment, and it has 

 apparently been freely floating about for a consider- 

 able period. I have since received a small sjaecimen, 

 not quite two inches long by one inch wide, without 

 the lobular projections, and hke the larger ones 

 without any indication of basal attachment. 



MiOROCiONA FicTiTiA, Platcs XXIII & LXXXII. 



Early in February, 1873, I received from Miss 

 Oliver, a dealer in natural-history specimens at 

 Hastings, several specimens of sponges fresh from off 

 the Diamond ground. Among them was an old oyster- 

 shell three inches in width, around the inside edge of 

 the gibbous shell there was a thick incrustation for 

 about an inch in width, and smaller patches were also 

 on the margin of the inside of the flat shell. When 



