145 



PLATE LVII. 



IsoDiCTYA Barleei, Boivevhanh. 



Vol. ii, p. 333, ' Mon. Brit. Spongiada3.' 



Fig. 1. — Represents a specimen of the species in the 

 dried state, of the natnral size, from the same locality 

 as the previously described ones. I am indebted to 

 my friend Mr. 0. W. Peach for this very illustrative 

 specimen. 



Fig. 2. — Represents a small portion of a section at 

 right angles to the surface of the sponge. X 80 

 linear. 



Fig. 3. — One of the slender, acuate, tension spicula 

 of the dermal membrane. X BO linear. 



Fig. 4. — One of the skeleton spicula. X 80 linear 



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