PLATE XLVI. 



Fig. 1. Pachychalina {?) punctata, dermal skeleton reticulation surrounding jo, one 



of the pores (?); pr, projection into the pore, . . . .24 



Fig. 2. Pac%cAaZma(?')pMnctoto, skeleton arrangement, as seen in vertical section, 24 



Fig. 3. Siphonochalina intermedia, skeleton arrangement, as seen in vertical 



section ; a, primary fibres ; b, secondary fibres, . . .30 



Fig. 4. Pachychalina lohata, surface section, showing the dermal skeleton reticu- 

 lation and the pores; d.s., dermal skeleton; d.m., dermal membrane; 

 p, pores, . . . . . . . . 22 



Fig. 5. Halichondria latrunculioides, dermal skeleton, . . . . g 



Fig. 6. Chalina rectangularis, skeleton arrangement, as seen in vertical section, . 28 



Fig. 7. Esperiopsis symmetrica, skeleton arrangement, as seen in longitudinal 

 vertical section ; a-a, imaginary long axis of sponge ; b, a band of 

 spiculo-fibre of the inner series ; c, a band of spiculo-fibre of the outer 

 series ; d, radiating fibres (part only shown); e, embryos, . . 77 



Fig. 8. Dendropsis bidentifera, skeleton arrangement, as seen in transverse sec- 

 tion ; a, central axis ; b, tufts of small spicules surrounding the laro-e 

 projecting spicules; c, small, spined oxea, . . . .192 



Fig. 9. Rhaphidophlus filifer, skeleton arrangement, as seen in vertical section ; 



(i.e., the characteristic dermal crust of spicules, . . .152 



