PLATE V. 



Fig. i (311 b). Placospongia carinata. a — £ six stages of development of sterrospira; r, and 5 

 adult sterrospirae; the outline and the surface view only partly indicated; 

 X 1400. 



Fig. 2 (1849 a). Placospongia melobcsioides. Early stage of sterrospirae-, x 1000. 



Fig. 3 (1849 a). ld. id. X 1000. 



Fig. 4 (1849 b). Id. id. X 1000. 



Fig- 5 (3 11 0- Placospongia carinata. Early stage of sterrospira; • 360. 



Fig. 6 (1849 a). Placospongia melobcsioides. Outline of adult sterrospira; X 360. 



F'&- 7 (577)- Placospongia carinata. Id. ; x 360. 



Fig. 8 (311 f). Id. a — y Transverse sections through a branch ; X 2. 



Fi&- 9 (3 11 0- ld- Longitudinal section through a part of a branch; nat. size. 



Fig. 10 (660 a). Placospongia melobesioides. Transverse section through the distal part of the 

 cortex; x 360. 



Fig. 11 (163 b). Placospongia carinata. Id. ; X 360. 



Fig. 12 (1033). Placospongia melobesioides. Id.; X 360. 



Fig. 1 3 (1033). Id. Portion of parenchyma with . two young sterrospirae and six groups of 

 spherules; X 360. 



Fig. 14 (1033). Id. Portion of proximal part of cortex (groove) with a group of spherules. 



