LIST OF THE PLATES. 



PLATE 



Portrait of Mr. JOSHUA ALDER, from a photograph in 

 the possession of the Eev. Canon Norman 



Frontispiece 

 I. Ascidia mamillata. 

 II. Ascidia mentula. 



III. details. 



IV. Figs. 1, 2. Ascidia nibicnnda. Figs. 3, 4. J.. 



Normani. 



V. Ascidia mollis. 



VI. Ascidia plana : blood-channels in mantle. 

 VII. Figs. 1-4. Ascidia rudis. Fig. 5. A. renosa. 

 Figs. 6-8. A. depressa. Figs. 9-11. A. aculeata. 

 VIII. Ascidia venosa : blood-channels in test. 



X. ,, branchial sac. 



XI. Figs. 1, 2. Ascidia amoena. Figs. 3-5. A.plebeia. 

 Figs. 6, 7. A. sordida. Figs. 8, 9. Probably a 

 variety of Corella parattelogramma. Fig. 10. 

 Ascidia obliqiia. 

 XII. Ascidia sordida. 



XIII. ,, reproduction. 



XIV. Ascidia Mon-i. 



XV. Figs. 1-7. Asddia scalra. Figs. 8^ 9. A affinis. . 

 XVI. Figs. 1-3. Ascidia pustulosa. Figs. 4-7. A. ellip- 



tica. Figs. 8, 9. A. pellncidn. 

 XVII. The branchial sac in Ascidia. 

 XVIIL- 



XIX. The mouth and oral lamina in Ascidia. 

 XX. The branchial tubercle in Ascidia. 



