THE CHEIROFTERYGIUM. 511 



This view of the cheiropterygium corresponds in some respects with that 

 put forward by 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 piscine 

 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 primitive Elasmobranch position into the 

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

 have been further rotated from this position into that which it occupies 

 in the adult Urodela and in all higher forms. 



BIBLIOGRAPHY of the Limbs. 



(477) M. v. Davidoff. "Beitriige z. vergleich. Anat. d. hinteren Gliedmaassen d. 

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



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

 zig, 18645. Erstes Heft. Carpus u. Tarsus. Zweites Heft. Brustflosse d. Fische. 



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

 genieinen u. d. Hintergliedmaassen d. Selachier insbesondere." Jenalsche Zeitschrift, 

 Vol. v. 1870. 



(480) C, Gegenbaur. " Ueb. d. Archipterygium." Jenaische Zeitschrift, Vol. vu. 

 1873. 



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

 Morphologisches Jahrbuch, Vol. n. 1876. 



(482) A. Gotte. Ueb. Entwick. u. Regeneration d. Gliedmaassenskelets d. Molche. 

 Leipzig, 1879. 



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

 classification of Fishes." Proc. Zool. Soc. 1876. 



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

 Trans., Vol. x. 



(485) A. Rosenberg. "Ueb. d. Entwick. d. Extremitaten-Skelets bei einigen d. 

 Reduction ihrer Gliedmaassen charakterisirteu Wirbelthiere." Zeit. f. wiss. Zool., Vol. 

 xxin. 1873. 



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

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



(487) H. Strasser. " Z. Entwick. d. Extremitiitenknorpel bei Salamandern u. 

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



(488) G. 'Swirski. Untermch. lib. d. Euticick. d. Schultergiirtels n. d. Skelets d. 

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



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

 of the Vertebrate limbs." Trans, of the Connecticut Acad., Vol. in. 1877. 



(490) J. K. Tbacker. "Ventral fins of Ganoids." Tram, of the Connecticut 

 Acad., Vol. iv. 1877. 



