434 
MESSRS. F. M. BALFOUR AND W. N. PARKER ON THE 
List of Reference Letters. 
a. 
Anus. 
a.b. 
Air-bladder. 
a.b'. 
Aperture of air-bladder into 
tbroat. 
a.c. 
Anterior commissure. 
a.f. 
Anal fin. 
al. 
Alimentary canal. 
ao. 
Aorta. 
ar. 
Artery. 
au. 
Auditory pit. 
b. 
Brain. 
b.c. 
Body-cavity. 
b.d. 
Bile duct. 
b.d'. 
Aperture of bile duct into duo¬ 
denum. 
bl 
Coalesced portion of segmental 
ducts, forming urinogenital 
bladder. 
br.a. 
Branchial arches. 
br.c. 
Branchial clefts. 
c. 
Pyloric caeca. 
/ 
c. 
Apertures of caeca into duo¬ 
denum. 
cb. 
Cerebellum. 
cd.v. 
Cardinal vein. 
ce. 
Cerebrum : in figs. 47 A and B, 
anterior lobe of cerebrum. 
of. 
Posterior lobe of cerebrum. 
cf. 
Caudal fin. 
cn. 
Centrum. 
ch. 
Choroidal fissure. 
CT.V. 
Circular vein of vascular mem¬ 
brane of eye. 
c.sh. 
Cuticular sheath of notochord. 
c.v. 
Caudal vein. 
d. 
Duodenum. 
d.c. 
Dorsal cartilage of neural arch. 
d.f. 
Dermal fin-rays. 
d. 1. 
Dorsal lobe of caudal fin. 
dl.f. 
Dorsal fin. 
e. 
Eye. 
ed. 
Epidermis. 
ep. 
Epiblast. 
fb. 
Fore-brain. 
fe. 
Pyriform bodies surrounding the 
zona radiata of the ovum, 
probably the remains of epi¬ 
thelial cells. 
g.h. 
Gall -bladder. 
g.d. 
Genital duct. 
gl 
Glomerulus. 
g.r. 
Genital ridge. 
h. 
Heart. 
h.a. 
Hsemal arch. 
h.b. 
Hind-brain. 
h.c. 
Head-cavity. 
lip. d. 
Hepatic duct. 
h.m. 
Hyomandibular cleft. 
h.op. 
Operculum. 
hy. 
Hypoblast ; in fig. 10, hyoid 
arch. 
hyl. 
Hyaloid membrane. 
i.c. 
Intercalated cartilaginous ele¬ 
ments of the neural arches. 
in. 
Infundibulum. 
ir. 
Iris. 
i.s. 
Interspinous cartilage or bones. 
i.v. 
Sub-intestinal vein. 
iv.r. 
Intervertebral ring of cartilage. 
k 
Kidney. 
l 
Lens. 
l.c. 
Longitudinal canal, formed by 
union of the vasa efierentia. 
l.in. 
Lobi inferiores. 
IX 
Ligamentum longitudinale supe- 
rlus. 
