CRANIAL NERVES 
OF SIREN LACERTINA 
249 
right angles with the other nerves which lie near it’’ (l.c.), re- 
quires some qualification. 
It is true of the root which passes to 
the posterior portion of the nasal epithelium, but is not true of 
the anterior trunk. Figure 2 shows the direction the roots take 
on emerging from the brain, and also the double origin of the 
nerve from the glomeruli. 
ABBREVIATIONS 
alv., vr. alveolaris VII 
alv.1, dorsal branch of r. aly. VII, in 
close relation with md. 4a 
alv.2, ventral branch of r. alv. VII 
alv.-pal., common trunk of rr. alveolaris 
and palatinus VII 
ao., antorbital cartilage 
aop., antorbital process 
sphenoid bone 
auo., ossification of the ear capsule 
aur., Yr. auricularis X 
bhy., basi-hyal cartilage 
br., brain 
br.1,X.1, branch of the second bran- 
chial nerve supplying the first gill 
br.2,X.1, branch of the second branchial 
nerve supplying the second gill 
br.2,X.2, branch of the third branchial 
nerve supplying the second gill 
br.3,X.2, branch of the third branchial 
nerve supplying the third gill 
buc., r. buccalis VII 
buc.1, r. bucealis, ventral division 
buc.2, r. bucealis, division anastomosing 
with r. oph. prof. V(op.4) 
buc.3, r. bucealis, lateral division 
buc.2+mz.2, union of buc.2 with fibers 
of r. max.V, to anastomose with r. 
oph. prof. V(op.4) 
buc.8+mz.3, union of buc. 3 with fibers 
of r. max. V, innervating side of head 
cbr.1, cbr.2, cbr.3, cbr.4, first, second, 
third and fourth ceratobranchial car- 
tilages 
cc., cranial cavity 
ecbl., cerebellar commissure 
of orbito- 
ch., cerebral hemisphere 
che., m. ceratohyoideus externus and 
branches of ther. jgl. VIT innervating 
it 
chi., m. ceratohyoideus internus and 
branches of the [IX and X nerves in- 
nervating it 
chy., ceratohyal cartilage - 
cp., petrosal cartilage = cartilaginous 
base of ear capsule 
cplx., choroid plexus ° 
dbr.1,dbr.2,dbr.3, depressor muscles of 
the first, second and third gills and 
the nerves innervating them 
dent., os dentare 
dl.1, branch of tr. int.-ace.X, innervat- 
ing dorsal portion of m.dorso-laryn- 
geus 
dl.2, branch of tr. int.-ace. X, innervat- 
ing middle portion of m. dorso-laryn- 
geus 
dl.3, branches of r. int.rec.X, innervat- 
ing ventral portion of m. dorso-laryn- 
geus 
dm., m. depressor mandibulae = digas- 
tricus = cephalo-hyo-mandibularis 
dma., anterior inner division of m. de- 
pressor mandibulae, and nerves in- 
nervating it 
dmp., posterior division of m.depressor 
mandibulae, and nerves innervat- 
ing it 
en., os ethmo-nasale of Parker, nasale 
of Cuvier 
e0., OS exoccipitale 
fe., fasciculus communis 
