THE SKULL. 191 



form, in the higher types. They are more developed in the Cyclostotnata 

 than in any other Vertebrate type. 



The meaning of these cartilages is very obscure ; but, from their being in 

 part employed to support the lips and horny teeth of the Cyclostomata and 

 the Tadpole, I should be inclined to regard them as remnants of a primi- 

 tive skeleton supporting the suctorial mouth, with which, on the grounds 

 already stated (p. -63), I believe the ancestors of the present Vertebrata 

 to have been provided. 



BIBLIOGRAPHY. 



(439) A. Duges. " Recherclies sur I'Osteologie et la myologie des Batraciens 

 a leur differents ages." Paris, Mem. savans etratuj. 1835, ami An. Sci. Nat. Vol. 

 i. 1834. 



(440) C. Gegenbaur. Untcrsucltitngen z. renjleich. Anat. d. Wirbelthiere, in. 

 Heit. Dos Kopfskelet d. Selachier. Leipzig, 187*2. 



(441) Gunther. Beob. lib. die Entwick. d. Gehm-ornans. Leipzig, 1842. 



(442) O. Her twig. " Ueb. d. Zahnsystern d. Amphibieu u. seine Bedeutung f. 

 d. Genese d. Skelets d. Muudhohle." Archivf. mikr. Aunt., Vol. xi. 1874, suppl. 



(443) T. H. Huxley. " Ou the theory of the vertebrate skull." Proc. lloyal 

 Soc., Vol. ix. 1858. 



(444) T. H. Huxley. The Elements of Comparative Anatomy. London, 186',). 

 ( 44 .s) T.H.Huxley. "On the Malleus and Incus." Proc. Zool. Soc., 1863. 



(446) T. H. Huxley. "On Ceratodus Forsteri." Proc. Zvol. So<:, 1876. 



(447) T. H.Huxley. " The nature of the craniofacial apparatus of Petromyzon." 

 Jouin. of Anat. and Plii/s., Vol. x. 187(5. 



(448) T.H.Huxley. The Anatomy of Vertebrated Animals. London, 1871. 



(449) YV. K. Parker. "On the structure and development of the skull of the 

 Common Fowl (Gallus Domestieus)." Phil. Trans., 1869. 



(450) W. K. Parker. "On the structure and development of the skull of the 

 Common Frog (Rana temper aria)." Phil. Trans., 1871. 



(^51) W. K. Parker. "On the structure and development of the skull in the 

 Salmon (Salmo salar)." Bakerian Lecture, Phil. Trans., 1873. 



(452) W. K. Parker. "On the structure and development of the skull in the 

 Pig (Bus sci of a)." Phil. Trans., 1874. 



(453) w - K- Parker. "On the structure and development of the skull in the 

 Batrachia." Part n. Phil. Trans., 1876. 



(454) W. K. Parker. "Ou the structure and development of the skull in 

 the Uiodelous Amphibia." Part in. Phil. Trans., 1877. 



(455) W. K. Parker. "On the structure and development of the skull in the 

 Common Snake (Tropidonotus natrix)." Phil. Tran-;., 1878. 



(456) W. K. Parker. " On the structure and development of the skull in Sharks 

 and Skates." Trans. Zoolon. Soc., 1878. Vol. x. pt. iv. 



(457) W. K. Parker.' "On the structure and development of the skull in the 

 Lacertilia." Pt. i. Lacerta agilis, L. viridis and Zootoca vivipara. Phil. Trans., 1879. 



(458) W. K. Parker. "The development of the Green Turtle." The Zooloipj 

 of the Voyage of H. M.S. Challenner. Vol. i. pt. v. 



(459) W. K. Parker. "The structure and development of the skull in the 

 Batrachia." Pt. in. P, U. Trans., 1880. 



(460) W. K. Parker and G. T. Bettany. The Morphology of the Skull. London, 

 1877. 



(460*) H. Rathke. Enticick. d. Natter. Konigsberg, 1839. 



(461) C. B. Reichert. " Ueber die Visceralbogen d. Wirbelthiere." Miillers 

 Archie, 1837. 



(462) W. Salensky. " Beitrage z. Entwick. d. knorpeligen Gehorknochelchen. 

 Murphul. Jahrbiich, Vol.'vi. 1880. 



Vide also Kolliker (No. 29'-!), especially for the human and mammalian skull; Ootte 

 (No. 296). 



