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PLATE LXXXVIII. 



ISODICTYA VAEIANS, Bowerbank. 



Fig. 1. A well-developed specimen of the species. 

 Natural size. In the collection at the museum of the 

 Public Free Library, Liverpool. 



Fig. 2. A small portion of the skeleton of the 

 sponge exhibiting the mode of the disposition of the 

 spicula and the variations in the structure of its primary 

 lines. X 127 linear. 



Fig. 3. Represents a small fragment of the skeleton 

 projecting from a section at right angles to its surface, 

 showing the mode of the intermixture of the various 

 forms of spicula in its reticulated structure. X 250 

 linear. 



Fig. 4. One of the sub-fusiformi-acerate skeleton 

 spicula. X 250 linear. 



Figs. 5 and 6. Two of the acuate spicula occasionally 

 mixed with the normal acerate, one in the skeleton 

 structures of the sponge. X 250 linear. 



ISODICTYA VAEIANS, Bowerbank. 

 Plate LXXXVIII. 



The type-specimen of this sponge in the Johnston 

 collection of British sponges in the British Museum is 

 a small fragment only of a larger specimen, and I 

 have much pleasure in figuring a very much more 

 satisfactory one which I obtained through the kind 

 assistance of Mr. T. Higgin, of Liverpool, and Mr. 

 Moore, of the Free Public Library and Museum of 

 Liverpool. 



Mr. Higgin informs me that the species has been 



