No. 3.] ZHE EMBRYOLOGY OF THE EARTHWORM. 
449 
EXPLANATION OF PLATES. 
Reference Letters. 
ar. Archenteron, ms. Mesoblastic cells. 
6, Blastopore. m. ms. Migratory mesoblast. 
c.g. Cephalic ganglia. mc. Muscle-cells. 
c.¢. Ciliated cells of the ventral sur- JV. Nephroblast. 
face. Vb. Neuroblast. 
Cephalic mesoblast, 
. Neural cord. 
c. p. Cleavage pore. np. Nephridium. 
ce. Ccelomic cavity. np. c. Nephric cord. 
d. Dissepiment. @, ¢c. (Esophageal collar. 
ec. Ectoblast. p. Proctodeum. 
en. Entoblast. p.¢. Prostomial or cephalic cavity. 
f- Funnel of nephridium or funnel- S. Seta. 
cell. s. ¢. Segmentation cavity. 
g: 6. Germ-band. s. gl. Setigerous gland. 
g. Ventral ganglion. s. m. Somatic mesoblast. 
z. Investing cells of nephridia. sp. Splanchnic mesoblast. 
7, v. Lateral vessel. st. Stomodzeum. 
Z. Lateral teloblast. 5.2 Schluckzellen or larval excretory 
2. c. Lateral cell-cord. organs. 
MM. Primary mesoblast. v. 2. v. Ventro-lateral vessel. 
Mouth, 
. Wentral vessel, 
