DIFFERENTIATIONS OF ECTODERM IN NECTURUS. 545 
35. Stannius.—‘ Das peripherische Nervensystem der Fische,’ Rostock, 
1849. 
36. Strone, O. S.— The Cranial Nerves of Amphibia,” ‘Journal of Mor- 
phology,’ vol. x, 1895. 
37. Wisun, J. W. van.—<‘‘ Ueber die Mesodermsegmente und die Entwickel- 
ung der Nerven des Selachierkopfes,’ Amsterdam, 1882. 
38. Winx, J. W. van.—‘‘ Ueber das Visceralskelett und die Nerven des 
Kopfes der Ganoiden und von Ceratodus,” ‘ Niederlandisches Archiv 
fiir Zoologie,’ 1882. 
39. Witson, H. V.—“The Embryology of the Sea-bass (Serranus 
atrarius),” ‘ Bulletin of the U.S. Fish Commission,’ vol. ix, 1891. 
EXPLANATION OF PLATES 36—38, 
Illustrating Julia B. Platt’s paper, “ Ontogenetic Differen- 
tiations of the Ectoderm in Necturus.” 
Lettering. 
a, a', b,c. Dividing cells. ar. Fore-limb. 6.4m. Branches of hyomandi- 
bularis vir. 471-3. First to third external gills. duc. Ramus buccalis yit. 
buc.p. Ramus buccalis profundus v. Dohrn’s “N. infra-maxillaris” in 
Selachii (8, p. 267). v. Wijhe’s “ramus maxillaris superior” of Ganoidei 
(88, p. 207). d'. Dorsal branch of glosso-pharyngeus. d®. Dorsal branch of 
vagus. ‘d./.l, Dorsal lateral line. d.7. Dorsal longitudinal ridge. end. 
Endoderm. ep. Epibranchial branch of vagus. ep.7. Epibranchial ridge. 
ep.s.0. Epibranchial sense-organs. ez. d'-*, Branches of glosso-pharyngeus 
and vagus supplying external gills. g/.s.o. Glosso-pharyngeal sense-organs. 
hm.v. Hyomandibular ridge. m.s.o. Hyomandibular sense-organs. 70.7. 
Infra-orbital ridge. io. s.0. Infra-orbital sense-organs. /. 4. Light band on 
each side of the body. /./.s.0. Sense-organs of the lateral line. 7.7”. Lateral 
nerve. m. Mouth. md. Ramus mandibularis v and vit. md. s.0. Mandi- 
bular sense-organs. mect. Mesectoderm. m././. Median lateral line. m. x. 
Motor nerve. m.7. Mandibular ridge. mz. Ramus maxillaris Vv. my!-0, 
Myotomes, first to eleventh. x. Nose. z.c¢. Neural crest. oph.p. Ramus 
ophthalmicus profundus v. opf.s. Ramus ophthalmicus superficialis viz. of. 
Ramus oticus vi. pal.e. Ramus palatinus externus vil. pal. 7. Ramus 
palatinus internus, chief palatine branch of the facialis. yp. ep.r. Primitive 
epibranchial ridge. p/}-8. Rami pharyngei 1x and x. p.¢r. Posterior trans- 
_verse ridge of the branchial region. so.7, supra-orbital ridge. so. s. 0. Supra- 
orbital sense-organs. sp.g. Spinal ganglia. sp. ~!, *. First and second spinal 
nerves. 7.7. Transverse (intersegmental) ridge. v. hm. s.o. Ventral hyo- 
