ASTROSCLERA WILLEYANA, THE TYPE OF A NEW FAMILY OF SPONGES. 467 





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Fig. C. An APPB0XI^UTELY median longitudinal section thkough the specimen kepbesented in Fio. 2. 



The skeletal canals in the upper part are seen to contain soft tissues, while those at the base are 

 empty. (The canals to the left, marked by oblique shading, contained broken fragments produced by sawing, 

 so that the nature of their contents could not be recognised.) a, a. Canals which have been filled in by the 

 growth of the skeletal elements bordering them. b. Region of the skeleton formed by overlapping layers of 



skeletal elements added on the outer surface. 



