PLATE XIII. 



FIG. 1. SplMfrolylus antarcticus. Section of young specimen (x 3). 



FIG. 2. Section of same ( x 20). 



FIG. 3. Dermal pores (x 100). 



FIG. 4. Inner surface of cortex showing terminations of pore canals (x 100). 



FIG. 5. Horizontal section of papilla ( x 15). 



FIG. fi. Vertical longitudinal section of papilla (x 15). 



FIG. 7. Diplodal flagellated chambers ( x 400). 



FIG. 8. Syihaerotylus rupitutn-s (Vosmaer) choanosomal tyle (X 10<>) ; 8a, head of the same (x 100). 



FIGS. 9, 10. Smaller tyle and sub-tyle from spread out ends of radiating fibres of skeleton (X ll!(i). 



FIG. 11. Cortical tyle, also found in choanosome between the main fibres (x 100). 



FIG. 12. Smallest kind of cortical tyle (x 100) ; 12a, the same (xlGO). 



FIG. 13. Exotyle (x l>0j ; l:ia, clavate head of same (425). 



