934 
PROFESSOR W. C. M‘INTOSH AND MR E. E. PRINCE ON 
LIST OF REFERENCE LETTERS. 
anus, 
a, 
abd, abdomen. 
ab. air-bladder. 
ae. anterior commissure, 
af. anal fin. 
al. alar expansion of scutum (ds.). 
ao, aorta. 
aob. aortic bulb, 
ar, artery. 
au. otocyst (early condition). 
auc, auditory capsule, 
aur. auricle. 
6. brain. 
be. body-eavity. 
bd. blastodisk (before segmentation). 
bdm. a (after segmentation). 
él. blastomeres. 
ble. blood-corpuscles. 
blr. urinary bladder formed by union of 
segmental ducts. 
bp. blastepore. 
br. blastodermie rim. 
bra. branchial arches. 
bre. + clefts. 
bs.  blastodermic shield. 
car. carina, or ventral ridge of early 
embryo. 
cart, cartilage. 
can, canal (auditory, &c.) 
caps. capsule. 
caud, caudal end of trunk. 
cb. cerebellum. 
cdv. caudal vein. 
ce. cerebrum, anterior fore-brain. 
ceph. cephalic end of embryo. 
cf. caudal fin. 
ch. choroidal fissure. 
cl. clavicle. 
cp. cortical protoplasm. 
cs. cuticular (hypoblastic) notochordal 
sheath. 
ct. cartilage, and connective tissue. 
ctr. cornu trabecule. 
cv. cardinal vein. 
de. ductus choledochus. 
df. dorsal fin. 
dg. dorsal or medullary groove. 
duc. ductus Cuvieri. 
é& eye. 
ed. epidermis. 
ef. embryonic (marginal) fin, 
ep. epiblast. 
CP-o 5, corneous. 
pny neurodermal. 
er. embryonic fin-rays. 
ja. anterior transverse fibres. 
fb. — fore-brain. 
fbr. roof of fore-brain 
fg. branchial ruaiments. 
JG. fornix of Gottsche. 
g. gut. Jy. fore-gut. 
mg. mid-gut. 
hg. hind-gut or rectum. 
b.  gall-bladder. 

germinal cavity. 
gl. glomerulus. 
h. heart. 
ha. hemal arch. 
hb. hind-brain. 
hg. hind-gut. 
hm. hyomandibular arch. 
hine. os cleft. 
hr. rudiment of heart. 
hyd. hyoid element. 
hyp. (or hy.) hypoblast. 
i. iter a tertio ad quartum ventri- 
culum. 
inf. infundibulum. 
inn. interneural (spinous) cartilages. 
ir. iris. 
iv.  subintestinal vein, 
k. kidney. 
Kv. Kupfler’s vesicle. 
i. lens. 
lr. _ liver. 
ll. lower layer (primary entoderm) 
cells, 
ly. lymphatic mass in front of kidney. 
Zi. lobi inferiores, 
m. mouth. 
ma. meridional areas of protoplasmic 
transference, 
mb. mid-brain. 
me. permanent medullary canal. 
md. and mo. medulla oblongata, 
me. mesenteron. 
mel. membrana elastica externa, 
mes. mesoblast. 
mg. wid-gut. 
mic. micropyle. 
mn. mandible. 
mro. wousculus retractor oris. 
msn. Mesentery. 
mx. maxillary. 
my. mmyotomes, muscular somites, or 
myomeres. 
nm. nucleus. 
na. neural arch. 
mc. notochord. 
nes. notochordal sheath. 
meu. nervous cushion (auditory). 
me. neurochord. 
nec. neurenteric canal. 
nic. cellular ring of notochord. 
np. nuclei of the periblast. 
nv. nerve. 
og. oleaginous sphere or globule. 
ol, nasal pits. 
olf. olfactory lobes. 
oln. 3 nerves. 
op. optic vesicle, also eye in later stages 
(oc. in some figures). 
ope. operculum, 
opem.optic commissure, 
opl. ,, lobes. 
oto. otoliths. 
ovf. valve-like flap of optic lobe 
p. — protoplasm. 

pou 
pigmented layer of choroid. 
perichordal (mesoblastic) sheath. 
. parachordals. 
pericardial chamber, 
periblast. : 
pectoral fin ; also pale commissural 
fibres. 
pectoral girdle, 
palpocils. 
pineal gland. 
primitive germinal cells. 
», _ opercular aperture, 
pq. or ptg. palato-quadrate cartilage. 
pr. (also my.) protovertebre. 
pronephric chamber. 
primitive streak. 
pronephros. 
a opening into pre. 
perivitelline space or ‘‘ breathing 
chamber.” 
pituitary body. 
pterygo-quadrate. 
portal vein. 
parietal zone of blastoderm (resem- 
bling the Avian zona pellucida), 
quad, quadrate part of mandibular arch. 
rib. 
swim-bladder. 
archinephrie or segmental duct. 
segmentation cavity. 
segmental tubes. 
sensory organs. 
somatic mesoblast. 
splanchnic mesoblast. 
spherules. 
spinal nerve. 
serous spaces around embryo. 
stomach. 
sinus venosus. 
thalamencephalon or posterior fore- 
brain. 
lobes of roof of thalamencephalon. 
floor of thalamencephalie chamber. 
trabecule. 
tori semicirculares, 
5, longitudinales. 
urinary vesicle. 
vesicle. 
ventricle (heart). 
ventral fins. 
vein. 
ventricle (brain). 
vesicle of thalamencephalon. 
blood-vessel. 
vanously used for special structures. 
yolk. 
yolk-sae or embryonic membrane. 
zona radiata. 

. Olfactory nerve. 
. Optie nerve. 
. Oculo-motor nerve. 
. Facial and auditory nerves. 
. Trigeminal nerve. 
