604 
MR. HUXLEY ON DOLIOLUM AND APPENDICULARIA. 
Fig. 6. Ovum and pedicle. 
Fig. 7- A young zooid developed by gemmation. 
Fig. 8. A young zooid separated and enlarged. Viewed from the ventral side. 
Fig. 9. Youngest form of gemma observed. 
Fig. 10. “Ciliated fossa,” with the ganglion and otolithes. 
a. 
Anterior extremity. 
P- 
Testis. 
b. 
Posterior extremity. 
q- 
Ovary, or rather ovum. 
n 
• 
Endostyle. 
q'- 
Pedicle. 
d. 
Ganglion and otolithes. 
r. 
Buccal orifice. 
e. 
Gill band. 
s. 
Anal orifice. 
/. 
Languet. 
t. 
Lobe of the stomach. 
O' 
i:> 
Heart. 
u. 
Tubular system. 
h. 
Gemmiferous tube (single gemma 
V. 
Branchial bars. 
in Pyrosoma). 
w. 
“ Ciliated sac.” 
i. 
Nucleus. 
X. 
“ Ciliated band.” 
k. 
Muscular bands. 
ce. 
Eleoblast. 
1 . 
Solitary foetus, or young Salpa A. 
a. 
External tunic. 
m. 
Placenta. 
Internal tunic. 
n. 
Sinus running specially to the pla- 
7- 
Partition of gemmiferous tube. 
centa. 
1. 
Cell masses in Pyrosoma. 
0. 
Dorsal sinus. 
PLATE XVIII. 
Fig. 1. Aj)])endicularia Jlagellum. Much magnified. 
Fig. 2. Still more magnified. 
Fig. 2®. Extremity of the caudal appendage. 
Fig. 3. Body of Appendicularia from behind. 
Fig. 4. Individual in which the testis is much enlarged. 
Fig. 5. Doliolurn denticulatum, from the right side. 
Fig. 6. Doliolurn dejiticulatum, from below. 
Fig. 7- A portion of the right wall to show the testis in situ. 
Fig. 8. The “ ciliated sac ” and the origin of the “ ciliated bands ” in Doliolurn. 
Fig. 9. The intestine and heart, with the commencement of the branchiae. 
The letters have throughout the same signification. 
a. 
Ganglion with the auditory vesicle. 
e,f. Ciliated bands. 
h. 
Nerve. 
g. Mouth. 
c. 
Endostyle. 
h. Oesophagus. 
d. 
Respiratory or anterior aperture. 
i. Stomach. 
