A MONOGRAPH OF THE 



Type, Grantia compressa, Jolinston. Vol. I, Plate XXI, 

 Figs. 312, 313, and Plate XXVI, Figs. 345, 

 346, a, b. 



2. LErcosoLENiA, Bowerbank. 



Grastia, Fleming and Johnston. 



Sponge. Fistulax. Formed of a single layer of triradiate 

 and other spicula, surrounding a large central cloaca, " 

 which extends into all parts of the sponge. Vol. I, 

 p. 164. 



Type, Grantia hotryoides, Fleming. Vol. I, Plate XXVI, 

 Figs. 347, 348. 



3. Leuconia, Grant. 



Gkiniia, Fleming and Johnston. 



Sponge. Furnished with cloacae, one or more. Parietes 

 of sponge formed of a mass of irregularly disposed 

 interstitial membranes, and triradiate and other 

 spicula; permeated by* sinuous excurrent canals, 

 the oscula of which are irregularly disposed over the 

 surfaces of the cloacae. Vol. I, p. 164. 



Type, Grantia nivea, Fleming. Vol. I, Plate XXVII, 

 Figs. 351, 352. 



4. Leucogypsia, Bowerbank. 



Sponge. Massive, without cloacae; formed of irregularly 

 disposed membranous tissues and spicula. Oscula at 

 the external surface. Vol. I, p. 165. 



Type, Leucogypsia Gossei, Bowerbank. Vol. I, Plate XXVI, 

 Figs. 349, 350. 



