PLATE XXXI. 



PAGE 



Fig. 1. Plocamia coriacea, Mir. elegant; x 2, . . . . 158 



Fig. 2. Echinuclathria glabra ; natural size. . . . . 163 



Fig. 3. Echinoclathria carteri; natural size. . . . 162 



Fig. 3a. End of a Inaiicli, enlarged ; ", o.scula : x lU. 



Fig. 4. Echinoclathria fttvus, ^roy;in^ uyuii -d I\-cte'ti ; nntural size, . 160 



Fig. 5. Echinoclathria favus, another specimen, also growing u])Oii ii Pccfeii ; 



natural size. . 1 60 



Fig. 5(1. Portion of fig. •'>, enlarged, showing the oscula {o), and. at iii, a delicate meiubrani 

 tynipanizing one of tlie larj,'e openings ; x .5. 



