REFERENCE TO PLATES. 303 



FIGURKS. PAGE. 



20. Embryo in eighth stage, from the back. 



21. Section of an advanced embryo. 1 represents the cephalic and 



'.} the abdominal portion of the inner yolk-sack. 



Plate 22. 



Development of Cephalopoda 46 



o. Mouth. D. Outer yolk-sack. T. Tentacles. J. Siphon. 



c. Eyes, c h. Button-like cartilage, b r. Branchiae, i. Vis- 

 ceral sack, b i. Ink-bag, o t. Otolithes. *. Salivary glands. 

 n. Stomach, r'. Blindsack. c. Heart, cbr. Branchial hearts. 



1 to "). Arms. I, 2, 3. Portions of the inner yolk-sack, head, 

 neck and stomach. 



1. Embryo of Sepia officiiialis, three or four times smaller than its 



yolk-sack. Kolliker, Entwicklungsgeschichte der Cephalo- 

 poden, t. 4, f. 88. 



2. Side view of the same. L. c., t. 3, f. 28. 



3. Dorsal view of a more developed embryo. 



4. A young Sepia officinalis, ventral view, the mantle cut open. 



Cuvier, Nouv. Ann. du Mus., i. 

 5 10. Yolk-sack in progressive stages of development. Kolliker, I.e. 



11. Portion of egg-cluster of Loligo vulgaris. Fer. et Orb. Ceph. 



12. Embryo of the same. Fer. et Orb. Ceph. 



13. A group of eggs of Argonauta argo, Fer. et Orb., I.e., t. 1 ter., f.6. 



14. Egg of Argonauta argo. Kolliker, 1. c. 



15,16. Ibid. Appearance of the mantle, head, arms, eyes. Kolliker. 



17. More advanced embryo of the same. Kolliker. 



18, 19. Matured embryos, dorsal and ventral views. Kolliker. 



Plate 23. 



I, 2. Octopus aranea. Fer. et Orb. Cephalopodes, t. 5, f. 1, 2 Ill 



3, 4. O. octopodia, Linn. O. vulgaris, Lam. D'Orb. in Sagra's 



Cuba, t. 1, f. 1, 2 113 



Plate 24. 



5. O. octopodia, Linn. O. vulgaris Lam. Fer. et d'Orb., t. 11... 113 



6. sucker. D'Orbigny, Moll. Viv. et Foss.. t. 1 113 



7. " O. vulgaris, Lam. Jeffreys' Brit. Conch., vol. v. . . 113 



Plate 25. 



8. O. Salutii, Verany. Cephal. Medit., t. 9 114 



9. O. rugosus, Bosc. O. granulatus, Lam. Fer. and d'Orb., 



t. 6, f. 1 116 



10. O. brevipes, d'Orb. Cephal., t. 17, f. 1 119 



II. O. hotridus, " t. 7, f. 3 119 



Plate 26. 



12. O. aculeatus, d'Orb. Cephal., t. 7, f. 1 120 



13, 14. O. aculeatus, beaks, d'Orb. Cephal., t. 23, f. 3, 4 120 



15. 16. O. lunulatus, Quoy and Gaimard. Voy. Astrol., t. 6, 1. 1, 2. 121 



Plate 27. 



O. tetracirrus. Chiaje. Verany, Ceph. Medit., t. 7 119 



O. superciliosus, Quoy and Gaim. Voy. Astrol., t. 6, f. 4 121 



