EXPLANATION OF THE PLATES. 



Plate 

 I. 



II. 

 III. 

 IV. 



V. 

 VI. 



VII. 

 VIII. 



IX. 

 X. 



XI. 



XII. 



XIII. 



XIV. 



XV. 

 XVI. 



XVII. 



XVIII. 



XIX. 



XX. 



XXI. 



XXII. 



XXIII. 



XXIV. 



XXV. 



XXVI. 



XXVII. 



XXVIII. 



XXIX. 



.2 '^ 



Ambulacral Plates &c. of species of "^ To illustrate the morpho- 



Coelopleuriis. I logy of the test of these 



Ambulacral Plates &c. of species of f genera by Prof. Duncan 



Arbacia. I and Mr. Sladen. 



Japanese CoLYDiiDiE, described by Mr. D. Sharp in his paper 



thereon. 

 Ceeithiopsis, species of, accompanying the Eev. E. Eoog Watson's 



article on Cerithiopsides from the North Atlantic. 

 Diagrams of Ambulacral Structures of recent Diadematidte, to 



illustrate Prof. Duncan's paper on their Anatomy. 

 Ceylonese Colydiid^, figures of species of, referred to by Mr. 



D. Sharp in paper upon. 

 Campanularia CAEDUELLAa?2c?Sertularella margaritacea. 

 Seetularella capillaris and S. crassipes. 

 S. cuneata and S. limbata. 

 S. trimdcronata and S. trichocarpa. 



S. DIFFUSA. 



DiPHASiA bipinnata and Synthecium ramosum. 

 Sertularia aperta, S. minima, and S. unilateralis. 



S. CRINIS. 



S. ELONGATA. 



S. CRiNOiDEA, S. amplectens, S. megalocarpa, and Thui- 



aria interrupta. 

 Desmoscyphus oeifissus and D. unguiculata. 

 Thuiaria diaphana and T. ramosissima. 

 T. HiPPisLEYANA and Thecocladium ilabellum. 

 Thuiaria heteromorpiia. 

 Aglaophenia chalcocaepa and A. perforata. 

 A. acutidentata and Halicornaria mitrata. 

 Halicornaria cornuta and Aglaophenia late-carinata. 

 Aglaophenia dolichocarpa and Gattya humilis. 

 Lytocarpus ramosus. 



Plumularia lagenifera and P. mu'ltinoda. 

 Stridulating Organ &c. of Sjpharothermm. 

 Antennary Sense-organ of Sfhcsrotherium. 

 Diagram of Tracheal and Nervous System 



of Sphcerotherium. 



1- ■ 



) ^ 



To illustrate Mr. 

 Gr. C. Bourne's 

 account of its 

 Anatomy. 



