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PLATE LXXXIX. 



DESMACIDON PANNOSUS, Bowerbank. 



Fig. 1. The type-specimen. Natural size. 

 Fig. 2. One of the acuate skeleton spicula. X 250 

 linear. 



ISODICTYA INCERTA, Boiverlank. 



Fig. 3. The type-specimen. Natural size. 

 Fig. 4. One of the large acerate spicula of the 

 skeleton. X 250 linear. 



TETHEA CRANIUM, Lamarck. 



Fig. 5. Represents the most perfect of the speci- 

 mens of pedicelled gemnrales of T. cranium sent to me 

 by Mr. Barlee. Natural size. 



Fig. 6. A view of the interior of a specimen sec- 

 tioned perpendicularly. Natural size. 



Fig. 7. Represents the external surface of the 

 specimen, figure 6. 



Fig. 8. Represents a portion of the section taken 

 from the inner surface of the same sponge as figure 6, 

 extending from the distal margin to very close to the 

 top of the pedestal, and exhibiting the continuation of 

 the skeleton fasciculi from the base to the apex of the 

 sponge. X 36 linear. 



MICROCIONA KENTIIJ Boiverbank. 



Fig 9. Represents the type-specimen of the species, 

 in the cabinet of Mr. W. Saville Kent. Natural size. 



