GE. JULD 
,一 Caudina. 
PLATE 6. 
A BBREVIATIONS, 
ager, Radial water canal. mat. ly. Longitudinal muscle fi- 
cl. fol. Follicular cell. bers of body-wall. 
em). Radial epineural canal. mu. lg.! Longitudinal muscle fi- 
eth. ex. External epithelium of bers of rudimentary 
Polian vesicle. ambulacral foot. 
eth. ei. O. External epithelium of mat. fr. Transverse muscles of 
the ovary. n. Nerve. [body-wall. 
e'th. i. Internal epithelium par. oa. Wall of the ovary. 
hp'n. v. Hyponeural canal. lis. cont. Connective tissue. 
lac. 04. Lacunar blood vessel of vt. ex. External layer of yolk. 
Mpy. Micropyle. [the ovary. yt. L. Internal layer of yolk. 
ma. Circular muscle fibers. Qi Zona radiata. 
Fig. Cross section of the stone canal. >< 12. 
Fig. 74. Section of the madreporic body, nearly perpendicular to its flat sur- 
faces. x 37. 
Fig. Longitudinal section through the wall of the Polian vesicle, X 535 
Fig. "ross section through the wall of the circular water canal. x 535. 
Fig. Longitudinal section through a tentacular canal and upper part of 
Fig. 
radial plate, showing the valve of the tentacle. x 280. 
Diagrammatic radial section through a tentacle showing the circula- 
tion of fluid in it. 
). Cross section through the posterior end of a radial water tube and its 
lateral vessels (rudimentary ambulacral feet) along the line AB of 
Fig. 80. x 280. 
80. Graphic reconstruction of the terminal tentacle (the anal papilla) and 
the two rudimentary ambulacral feet. Scale 08 p to 1 mm, or 
x 150. 
Peritoneal epithelium from the wall of the ovary. Maceration prepa- 
ration, X 240, 
The same. Silver-nitrate preparation. X 240. 
Part of a cross section of wall of ovary ofa young individual. x 720. 
Muscle fiber from the wall of the ovary. X 205. 
Follicular epithelium. | Silver-nitrate, X 240. 
"art of cross section of wall of ovary of Cucumaria frondosa. X 240. 
Young ovum. x 235. 
Figs. 88,89. Slightly older stages in the growth of the ovum. x 235. 
Fig. 90. 
Fig. 
Ovum showing deep staining of a superficial layer, preparatory 
formation, of a zona radiata. X 235. 
Ovum showing two layers of yolk separated by intravitelline mem- 
brane. X 235. 
EE 
0 
ig. 92. Surface view of interior of ovary showing a well-grown ovum in posi- 
tion and the mieropyle projected on the verminative vesicle. X 226. 
pyle pro) g 
Section of a nearly full-grown ovum.  Fol’s chromic-osmic-acetic 
mixture. Ehrlich’s haematoxylin and eosin. X 235. 
