0 ee 
HO. .T.'| 
EVES OF ARTHROPODS. 
175 
EXPLANATION OF LETTERS USED IN THE PLATES. 
first pair of antennz; labrum. 
second pair of antennz. 
nuclear-like bodies. 
antennary lobe. 
amnion. 
nerve to second antenna. 
appendage to eye I. 
. nerve to appendage of eye I. 
axial nerve. 
brain. 
bridge over ganglionic invagina- 
tion. 
basement membrane = outer 
‘neurilemma. 
clear area. 
1 convex eye. 
. corneagen. 
corneagen; median part with 
faint nuclei. 
corneagen of appendage. 
cuticula that gives rise to lens. 
cavity of ganglionic invagina- 
tion. 
corneal cuticula. 
cavity of the optic vesicle. 
cuticula thickening = retinidial 
cuticula. 
dark areas. 
dividing nuclei. 
eyes. 
endoderm. 
cavity in endoderm. 
external nerve fibres. 
frontal ganglion. 
great ganglion cells of optic gan- 
glion. 
double ganglion cell of optic 
ganglion. 
ganglion cell of retina. 
great rods. 
ganglionic invagination. 
heel of great retinal cells. 
medulla of the horizontal retina. 
horizontal retina of eye I. 
. horizontal rods. 
iris. 
inner neurilemma. 
infra-cesophageal ganglion. 
4. 7A. 
me. 
mM. C. 
m. b. 
ma. 
md. n. 
m. h. 
0.0.0: 
mn. fr. 
ML. £. 
LSE Nia 
mM. 0. 
mM... 
ms. 
Ml. V. 
mx.A-2 
ni-ViL 
ni-8 
nca-3 
n. f 
inverted rods of outer wall of 
optic vesicle. 
lens. 
loops of axial nerve. 
. lateral nerve of horizontal retina. 
mouth. 
medulla of the appendage to 
eye I. 
muscles. 
median chord. 
medulla of the brain. 
mandibles. 
mandibular nerve. 
medulla to horizontal retina. 
medulla to inverted cells. 
median furrow. 
median row of giant cells. 
median row of giant rods. 
cesophageal muscles. 
median ridge. 
mesoderm. 
medulla of vertical retina. 
maxillee. 
nerves to the eyes. 
nerves to the sense organs in 
eyes. 
large nuclei. 
nerve fibres. 
nerve fibrillze. 
newly formed ganglion cells. 
outer ends of ganglion cells that 
have passed inwards. 
primary nuclei of retinophore. 
secondary nuclei of retinophorze. 
nerve spindles. 
cesophagus. 
cesophageal commissures. 
optic ganglion. 
outer neurilemma. 
opening of optic cavity. 
optic plate. 
outer wall of optic vesicle. 
outer wall of optic ganglion. 
. pigmented nerve fibres. 
. place where optic ganglion is 
continuous with the optic 
plate. 
