SKATE. 279 



to the hypoblast. They thus contribute to its growth, and especially 

 to the formation of the floor of the alimentary canal. 



The chief works on the Anatomy of the Skate and Elasmobranchii are the 

 following : 



Anatomy of Skate, T. J. Parker, Zootomy, London, 1884. 



Zoological account of Rays. Cf. Day, Fishes of Great Britain and Ireland, ii. 

 1884, p. 336. Couch, Fishes of British Islands (coloured figures), i. 1862, p. 78. 

 Bell, British Fishes, ii. 1841, p. 550. Giinther, British Museum Catalogue of 

 Fishes, viii. 1870, p. 434. 



Skull. W. K. Parker, Tr. Z. S. x. 1879. Visceral arches. Dohrn, Mitth. 

 Zool. Stat. Naples, vi. 1885. 



Paired fins. Balfour, P. Z. S. 1881. Paired and azygosfins. Mivart, Tr. Z. S. 

 x. 1879 (see general remarks). Azygos fins. Mayer, Mitth. Zool. Stat. Naples, 

 vi. 1885. 



Exoskeleton. Hertwig, J. Z. viii. 1874. Benda, A. M. A. xx. 1882. 



Teeth. Tomes, Ph. Tr. 1876. Id. Dental Anatomy, ed. 2, 1882, p. 215. 



Central nervous system. Rob on, Dk. Akad. Wien, xxxviii. 1878. Viault, 

 A. Z. Expt. v. 1876. Systeme ganglionaire. Vignal, A. Z. Expt. (2), i. 1883, p. xvii. 

 Spinal cord, Stieda, Z. W. Z. xxiii. 1873 ; Sanders, P. R. S. xl. 1886. 



Cranial nerves. Marshall, Q. J. M. xxi. 1881. Cf. Beard, Branchial sense- 

 organs, Q. J. M. xxv. 1885. Vagus nerve. Rohon, Arb. Zool. Inst. Wien, i. 1878. 



Gustatory organs. Todaro, A. Z. Expt. ii. 1873. Organs of lateral line. 

 Solger, A. M. A. xvii. 1880. Do. and ampullae. Merkel, Endigungen der sensibeln 

 Nerven in der Haut, Rostock, 1880. 



Intestinal spiral valve. T. J. Parker, Tr. Z. S. xi. 1880. Rectal gland. 

 Blanchard, Journal de 1'Anat. et Physiol. xiv. 1878. ^Function of do. Id. Bull. 

 Soc. Zool. de France, vii. 



Rudimentary gill slits. Van Bemmelen, Mitth. Zool. Stat. Naples, vi. Histo- 

 logy of gills. Droscher, A. N. 48, 1882. Rudiment of air bladder. Miklucho- 

 Maclay, J. Z. iii. 1867. 



Valves in conus arteriosus of Elasmobranchii and Ganoidei. Stohr, M. J. ii. 

 1876 ; for Raja Batis, see p. 219. 



Venous system of Skate. T. J. Parker, Trans. New Zealand Institute, xiii. 1880. 



Urinary apparatus and genital ducts. Balfour, Development of Elasmobranch 

 Fishes, 1878, pp. 249-286. 



Ovary. Balfour, Q. J. M. xviii. 1878. Cf. J. Muller, Berlin, Abhandl. 1840, 

 for forms of ovum, and Giinther, Study of Fishes, 1880. 



Copulatory organs. Petri, Z. W. Z. xxx. 1878 ; see Bolau, Z. W. Z. xxxv. 1881; 

 and Schneider, Zool. Beitrage, i. i. 1883. 



Pori abdominales. Bridge, Journal of Anat. and Physiol. 1879. Cf. Ayers 

 and Gegenbaur, M. J. x. 1884. 



Chemistry of horny fibres in Mustelus and egg-case of Scyllium. Krukenberg, 

 Mitth. Zool. Stat. Naples, vi. 1885. 



