EMBRYOLOGY OF THE SEA BASS. 
273 
COMMON REFERENCE LETTERS USED IN THE FIGURES— Continued. 
c, ep. 
Columnar epithelium of lens invagina- 
n. s. 
Nasal sac. 
tion. 
nc. s. 
Notochordal sheath. 
ce}\ 
Cerebellum. 
nc. 
Notochord. 
con, st. 
Connecting strand, bwt. organs 
of de- 
nr. ch. 
Neural chord. 
veloping lateral line. 
n.f. 
Neural furrow. 
c. 
Central periblast. 
op. s. 
Optic sac. 
cor. p. 
Cortical periblast. 
op. 1. 
Optic lobes. 
c, m. 
Caudal mass. 
oes. 
CEsophagus. 
d. 1. 
Dorsal lip of blastopore. 
0 . g. 
Oil globule. 
d. 1. s. t 
Dorso-lateral sense tract. 
0 . g. p. 
Protoplasmic cap of oil globule. 
d. 1. m. 
Dorso-lateral muscle tract. 
P- 
Periblast. 
d.f. 
Dorsal part of embryonic fin. 
p. pi. 
Periblast plug — Dotterpropf. 
d, n. r. 
Dorsal root of spinal nerve. 
p. a. g. 
Postanal gut. 
€. p. r. 
Early periblastic ridge. 
p. c. 
Pigment cell. 
ep. 5 . 
Epidermic stratum. 
pec, /. 
Pectoral fin. 
e, €. 8, 
Edge of embryonic shield. 
p. UK 
Periblast wall. 
ec. 
Ectoderm. 
p.p. 
Posterior pole of blastoderm. 
€. m. 
Egg membrane. 
pr. h. 
Primitive hypoblast. 
en, nies. 
Layer of cells which posteriorly becomes 
pr, str. 
Primitive streak. 
entoderm, anteriorly mesoderm. 
ret. L 
Retinal layer of optic cup. 
en. 
Entoderm. 
8. f. 
Sensory furrow — Common anlage for ear, 
/• gr- 
Fin groove. 
lateral line, and branchial sense organ. 
g. g. 
Gill slit. 
sec, c. m. 
Secondary caudal mass (remnant of ex- 
g. r. 
Germ ring. 
tra-embryonic germ ring). 
h. 
Heart. 
8om, 
Somites or somite mesoderm. 
h. e. 
Head end of embryo. 
8p. c. 
Spinal cord. 
Iter. 
Iter a tertio ad quartum Ven. 
s. 71. r. 
Subnotochordal rod. 
k. V. 
Kupffer’s vesicle. 
8. c. 
Segmentation cavity. 
1. en. 
Lateral entoderm. 
8. g. c. 
Subgermiual cavity (late stage of seg- 
In. 
Lens. 
mentation cavity). 
1. 1. 
Lateral line anlage. 
t. f. 
Tail furrow. 
1. 1. 0.1 
Ist organ of lateral line. 
till. mes. 
Undivided mesoderm in tail. 
1. 1. 0.2 
2d organ of lateral line. 
V. 1. 
Ventral lip of blastopore. 
1. 1. 0.’ 
3rd organ of lateral line. 
V. 1. m. 
Ventro-lateral muscle tract. 
1. 1. o." 
4th organ of lateral line. 
v.f. 
Ventral part of embryonic fin. 
1. 
Liver. 
V. n. r. 
Ventral root of spinal nerve. 
1- /- 
Lens fibers. 
V. mes. 
Ventral mesoderm (non-embryonic part 
1. ep. 
Lens epithelium. 
of germ ring). 
med. 
Medulla. 
w. d. 
Wolffian duct. 
m. con. 
Constriction separating medulla 
from 
w. c. 
Wandering cell. 
mid-brain. 
y- 
Yolk. 
m. hr. 
Mid-brain. 
1 d. 
1st cleavage plane. 
m. h. 
Muscle band (?) of coelom wall. 
2d. 
2d cleavage plane. 
m. c. 
Marginal blastoderm cell. 
3d. 
3d cleavage plane. 
m. ep. c. 
Marginal epidermic cell. 
id. 
4th cleavage plane. 
meg. 
Mesoderm. 
3 ven. 
Third ventricle. 
n. sir. 
Neurentric streak. 
4 veil. 
Fourth veneticle. 
The several series of sections are numbered from behind forwards. Objectives and oculars referred 
to are Zeiss’s. 
Bull. U. S. F. C. 89 18 
