THE CIIEIROPTERYGIUM. 511 



This view of the cheiropterygmm corresponds in some respects with that 

 put forward bj Gotte as a result of his investigations on the development 

 of the Urodele limbs, though in other respects it is very different. A diffi- 

 culty of this view is the fact that it involves our supposing that the radial 

 edge of the limb corresponds with the metapterygial edge of the pis'ine 

 fin. The difficulties of this position have been clearly pointed out by 

 Huxley, but the fact that in the primitive position of the Urodele limbs 

 the radius is ventral and the ulna dorsal shews that this difficulty is not 

 insuperable, in that it is easy to conceive the radial border of the fin to 

 have become rotated from its pi-imitive Elasmobranch position into the 

 vertical position it occupies in the embryos of the Urodela, and then to 

 liave been further rotated from this positi(>n into that which it occupies 

 in the adult Urodela and in all higher forms. 



Bibliography of the Limhs. 



(477) M. V. Davidoff. "Beitrage z. vergleich. Anat. d. hinteren Gliedmaassen d. 

 Fische L" Morphol. Jahrbiich, Vol. v. 1879. 



(478) C. Gegenbaur. Untersuchungen z. vergleich. Anat. d. Wirbelthiere. Leip- 

 zig, 1864 — 5. Erstes Heft. Carpus u. Tarsus. Zweites Heft. Brustflosse d. Fische. 



(479) C. Gegenbaur. "Ueb. d. Skelet d. Gliedmaassen d. Wirbelthiere im All- 

 gemeinen u. d. Hintergliedmaassen d. Selachier insbesondere." Jenaische Zeitschrift, 

 Vol. V. 1870. 



(480) C. Gegenbaur. " Ueb. d. Archipterygium." Jenaische Zeitschrift, \o\.yu. 

 1873. 



(481) C. Gegenbaur. " Zur Morphologie d. Gliedmaassen d. Wirbelthiere." 

 Morphologisches Jahrbuch, Vol. 11. 1876. 



(482) A. Gotte. Ueb. Entwick. u. Regeneration d. Gliedmdossenskelets d.MolcJie. 

 Leipzig, 1879. 



(483) T. H. Huxley. "On Ceratodus Forsteri, with some observations on the 

 classification of Fishes." Proc. Zool. S>oc. 1'87<>. 



(484) St George Mivart. "On the Fins of Elasmobranchii." Zoological 

 Trans., Vol. x. 



(48-;) A. Rosenberg. " Ueb. d, Entwick. d. Extremitaten-Skelets bei einigen d. 

 Reduction ihrer Gliedmaassen chara,kt«ri8irten Wirbelthiere." Zeit.f. iciss. Zool., Vol. 

 XXIII. 1873. 



(486) E. Rosenberg. "Ueb, d. Entwick. d. Wirbelsaule u. d. centrale carpi d. 

 Menschen." Morphologisches Jahrbuch, Vol. i. 1875. 



(487) H. Strasser. " Z. Entwick. d. Extremitatenknorpel bei Salamandem u. 

 Tritouen." Morphologisches Jahrbuch, Vol. v. 1879. 



(488) G. 'Swirski. Untersuch. iib. d. Entwick. d. Schultergiirtels u. d. Skelets d. 

 Brtistjlosse d. Hechts. Inaug. Diss. Dorpat, 1880. 



(489) J. K. Thacker. "Median and paired fins. A contribution to the history 

 of the Vertebrate limbs." Trana. of the Connecticut Acad., Vol. iii. 1877. 



(490) J. K. Thacker. "Ventral fins of Ganoids." Trans, of the Connecticut 

 Acad., Vol. IV. 1877. 



