AN ICHTHYOBDELLID PARASITIC ON SAND WHITING. 41 
of a specimen 7 mm. long. The section passed through the eleventh 
nerve ganglion and is cut obliquely so that the terminal part of the 
ejaculatory canal ( Ej . t.) is shown on the right side and the main mass 
of the spermatophore glands on the left (Sp. gl.). The terminal parts 
of the ejaculatory canals are seen just before they have united to form 
the spermatophore sac (compare with fig. 12a). The ventral vessel 
is seen lying free in the ventral lacuna, here expanded to contain the 
sexual organs. The relations of the ejaculatory canals, oesophagus 
and dorsal vessel in this region are also shown. D. v. Dorsal vessel. 
Ej. t. Terminal part of ejaculatory canal. Ej. c. Ejaculatory canal. 
N.gn. 11. Nerve ganglion 11. (Es. (Esophagus. Sp.gl. Spermatophore 
glands. V.v. Yentral vessel. 
Fig. 12a. — Diagram in relief of the Reproductive System. The 
terminal part of the right ejaculatory canal (Ej. t.) is shown as cut 
away for the sake of clearness. The relations of the ventral nerve 
cord and ganglia to the male and female organs are made evident. 
B. gl. Glandular part of the female bursa. Ej. c. Ejaculatory canal. 
Ej. t. Terminal part of the ejaculatory canal. Ovd. Oviduct. Ov. 
Ovaries. Sp. s. Spermatophore sac. V. def. Yasa deferens. V. ne. 
Yentral nerve cord. 11, 12, 13. Nerve ganglia. <$ Male opening. 
^ Female opening. 
