260 MR. A. K. TOTTON ON 
may be seen anteriorly in adult Selachians and in the Sturgeon, 
but it has not been shown before, as far as I am aware, in 
Teleosts. 
BIBLIOGRAPHY. 
(See O. Hertwig, 1906. Jena. Entwickelungslehre der Wirbeltiere, 
Bd. III. Teil 2, Kap. vi. pp. 456-82.) 
Srannius. 1854. Handbuch der Anatomie der Wirheltiere, 
2 Aufl. 1854. (Siebold u. Stannius, Handbuch d. Zootomie, 
Theil ii. Heft i. Berlin, 1854-56.) 
A. Kouurker. 1860. Ueber das Ende der Wirbelsaiule der 
Ganoide und einiger Teleostier. Leipzig. 
Lorz. 1864. Ueber den Bau der Schwanzwirbelsiule der 
Salmoniden, etc. Zeitschr. wiss. Zool. Bd. xiv. 
Grasst. 1883. (Développement de la colonne vertébrale chez 
les poissons osseux. Archiv. Ital. biologie, t. iv. 1883.) 
Lo svilluppo della colonna vertebrale ne pesci ossei. Reale 
Acead. dei Lincei, ser. 3, Memorie, vol. xv., 1882-83. 
Scueet. 1893. Beitriige zur Entwicklungsgeschichte der 
Teleostierwirbelsiiule. Morphol. Jahrb. Bd. xx. Leipzig. 
vy. Epner. 1896. Ueber die Wirbel der Knochenfische und die 
Chorda dorsales der Fischer und Amphibier. Sitzungsber. 
d. k. Akad. d. Wiss. Wien, Math.-Nat. K1., Bd. ev. 
Ussow. 1900. Zur Anatomie und Entwickelungsgeschichte 
der Wirbelsiule der Teleostier. Moskva, Bull. Soc. Nat., 
Ney Seplve ae ullis0)) 
Auprecut. 1902. Zur Ent. des Achsenskelettes der Teleostier. 
Tnaugural-Dissertation d. math. und nat. Fak. d. Kaiser- 
Wilhelms-Univ. zur Erlang. d. Doktorwiirde. Strassburg. 
A. Acassiz. 1878. On the Young Stages of some Osseous 
Fishes. Boston, Mass., Proc. Amer. Acad. Arts Sci. 
Ol stusl, 1On WINE 
ea elpxennve 8092 %@). Ji. Mess vole wie so.a4 Le 
J.A.RypEr. 1884. Washington, D.C., Rep. U.S. Comm. Fish. 
SOD. 
1a H. Wuitrnouse. 1910. Caudal Fin of Teleostomi. P. Z.S8. 
p. 990. 
C. T. Regan. 1913. Trans. Roy. Soc. Edinb. xlix. 
EXPLANATION OF THE PLATES. 
PuateE I. 
Fig. 1. Tail end of a specimen of Pleuragramma antarcticum, 8 mm. long. The 
specimen was stained, cleaned, and mounted whole in Canada balsam. 
The skleroblastic tissue, sk, is represented semidiagrammatically by dots. 
Notice the down-bending of the tip of the notochord. 
2. Tail end of a specimen of P. antarcticum, °85 em. long. Camera-lucida 
sketch from a whole mount. Notice down-bending of the tip of the 
notochord, the formation of definite cartilaginous elements, a’, a’’, by the 
skleroblastic tissue, and the appearance of lepidotrichia, 7p. 
