ABBREVIATIONS. 
a. Anterior. mb. vel. Intercellular membrane. 
ax. n. Axis of nerve fibrille. mb. n. opt. Membrane of optic nerve. 
brs. oc. Optic pocket. mb. pi’ph. Peripheral membrane. 
cl. con. Cone cell. ‘mb. pr’con. Preconal membrane. 
cl, ern. Cell of corneal hypodermis. mu. Muscle. 
cl. dst. Distal retinular cell. n. fbr. Nerve fibre. 
cl. hyl. Hyaline cell. nl. con. Nucleus of cone cell. 
cl. ms’drm. Mesodermic cell. nl. crn. Nucleus of cell in corneal hy- 
cl, px. Proximal retinular cell. podermis. 
cl. rtn/ Retinular cell. nl. dst. Nucleus of distal retinular cell. 
cl. rud. Rudimentary retinular cell. ni. h’drm. Nucleus of hy podermal cell. 
ench. Shell. nl. hyl. Nucleus of hyaline cell. 
cel. Body cavity, nl. ms’drm. Nucleus of mesodermice cell. 
con. Cone. nl. px. Nucleus of proximal retinular 
cp. sng. Blood corpuscle. cell. 
crn. Corneal cuticula. nl. rtn.’ Nucleus of retinular cell. 
cta. Cuticula. n. opt. Optic nerve. 
d. Dorsal. oc. Eye. 
dsc. Sucking disk. omm.’ Ommateum. 
dz. Right. p: Posterior. 
gn. opt. Optic ganglion. po. brs. Pore of optic pocket. 
h’drm. Hypodermis. r. Retina. 
hp. Liver. rhb. Rhabdome. 
mn. Intestine. rhb’m. Rhabdomere. 
Ins. Lens. rtn.’ Retinula. 
mb. ba. Basement membrane. S. Left. 
mb. crn. Corneal membrane. v. Ventral. 
mb. ern’con. Corneo-conal membrane. va. sng. Blood-vessel. 
Such other abbreviations as have been used are explained in the description of 
the figures with which they occur. 
