566 
CAPTAIN E. W. SHANN ON 
limb ; it is not thus functionally an adductor, though, from its origin on the dorsal 
aspect of the cleithrum, it should probably be regarded morphologically as a part of 
the adductor system. The claviculo-radiale externus does not supply the posterior 
rays, Hamburger’s “ opposable portion” of the fin. So far I agree, but it is surely 
a slip which leads him to say that this muscle draws the fin rays upwards, while the 
claviculo-radiale internus draws them downwards. 
The writer is indebted to the Carnegie Trust for a grant to cover the greater 
part of the cost of the illustrations. 
LITERATURE. 
(1) Agar, YV. E., “The Development of the Anterior Mesoderm, and Paired Fins, with their Nerves 
in Lepidosiren and Protopterus,” Trans. Roy. Soc. Edin., vol. xlv, 1907, pp. 611-39. 
(2) Anthony, R., “Adaptation a la vie arboricole chez les Vertebres,” Ann. des Sci. Nat. ( Zool. ), xv, 
2-6, 1912. 
(3) Allis, E. P,, “ The Skull, and the Cranial and First Spinal Muscles and Nerves, in Scomber 
Scomber," J. Morph., v, 1903, pp. 45-328. 
(4) Balfour, F. M., “On the Development of the Skeleton of the Paired Fins of Elasmobranchs,” 
Proc. Zool. Soc. London, 1881.- 
(5) Balfour, F. M., and Parker, W. H., “On the Structure and Development of Lepidosteus,” Phil. 
Trans., 1882. 
(6) Bolk, L., “Beziehungen zwischen Skelet, Muskulatur u. Nerven d. Extremitaten, dargelegt am 
Beckengiirtel, an dessen Musk, sowie am Plexus lumbosacralis,” Morph. Jahrb., xxi, Leipzig, 
1894. 
(7) Bolk, L., “Kekonst. der Segmentierung d. Gliedmassenmuskulatur, dargelegt an den Musk, des 
Oberschenkels u. des Schultergiirtels,” op. cit., xxii, 1895. 
(8) Bolk, L., “Die Sklerogonie des Humerus, zugleich ein Beitrag zur Bildungsgeschichte dieses 
Skeletteiles,” op. cit., xxii. 
(9) Braus, H., “ Innerv. paar. Extremit. bei Selach.,” Jena. Zeit. f. Naturw., xxix, 1895, and xxxi, 
1898. 
(10) Braus, H., “ Extremitatenskelettes,” Haeckelfest. Denkschr., Med.-Nat. Ges., Jena, 1904. 
(11) Braus, H., “Die Musk. u. Nerv. der Ceratodusflosse,” Zool. Forsch., op. cit., 1901. 
(12) Braus, H., “Extremit. u. d. Ex.-skelettes Hertwig’s Handb. Wirbelt., 1904. 
(13) Braus, H., “ Ueber neue Funde versteinertes Gliedmassenknorpel u. Musk, von Selach.,” Verh. d. 
Phys.-Med. Ges., Wurzburg, xxxiv, 1901. 
(14) Braus, H., “Die Nervengellechte d. Haie u. Rochen,” Jena. Zeit., xlvii, 1911. 
(15) Bruch, C., Osteol. des Rheinlachses, 2te Ausg., Mainz, 1875. 
(16) Budgett, J. S., “On the Structure of Larval Polypterus,” Trans. Zool. Soc., xvi, p. 315, 1902. 
(1.7) Buist, T. P., “Development of the Pectoral Girdle in the Pipe-fish (Syngnathus acus)," Ann. and 
Mag. Nat. Hist., Dec. 1912. 
(18) Cope, E. D., “The Homologies of the Fins of Fishes,” Amer. Nat., 1890, p. 418. 
(19) Corning, H. K., “Ueber d. vent. Urwirbelknospen in der Brustflosse d. Teleostier,” Morph. Jahrb., 
xxii, Leipzig, 1895. 
(20) Davidoff, Y. M., “Hint. Gliedmasse der Fische,” op. cit., 1879, 1880, 1883. 
(21) Dean, B., “Historical Evidence of the Origin of the Paired Limbs of Vertebrates,” Amer. Nat., 
1902. 
