394 WILSON. 



EXPLANATION OF PLATE XIX. 

 (Tedania Brucei.) 



Fig. 6o. Portion of surface of adult, showing the meandering ridges and fur- 

 rows. X 8. 



Fig. 6i. Section of adult, vertical to surface — arrangement of gelatinous and 

 spongy tissue, and skeleton. X lo. 



Fig. 62. Transverse section through base of oscular papilla. X 5. 



Fig. 63. Transverse section near oscular end of young sponge, 6 inches high. 

 X 10. 



Fig. 64. Vertical section of adult — arrangement of canals in gelatinous and 

 spongy regions. A. 4. 



Fig. 65. Section of adult — disposition of the ultimate branches of the 

 canals. D.4. 



Fig. 66. Dermal membrane. D.4. 



