148 THE ANATOMY OF AMPHIPTYCHES URNA. 
DESCRIPTION OF PLATES. 
Prats il. 
Fie. 1.—Diagrammatic representation of an adult specimen of Amphzptyches, 
drawn from the dorsal surface, to show the principal structures. At the anterior end 
the rosette of folds is seen, and at the posterior the sucker. ¢o. opening to exterior 
of excretory organ; mo. opening of male organs; 2. lateral nerve cord (this is 
represented as lying farther away from the median line than it does naturally) ; 7. 
posterior commissure uniting the nerve cords in the region of the sucker; mr. nerve 
ring around the proboscis; o. the scattered grape-like ovaries at the anterior end ; 
o' central cavity into which the ova pass before reaching the uterus. From this a 
fine (unlettered) duct is represented as passing to the receptaculum (7s.), this may 
possibly serve as a channel by means of which spermatozoa reach the ova; f. 
proboscis. At the posterior end the letters p. and o. respectively indicate the papilla 
on which the vas deferens opens, and the tube leading from this to the male opening. 
ry. receptaculum seminis; 7. s. 0. opening of duct running along the dorsal median 
line to the receptaculum ; s. sucker at the posterior end; ¢. the scattered testes at 
the posterior end; wé. uterus containing ova enclosed in shells; vs. vesicula seminalis 
into which the ducts form the testes oper ; yk. yelk glands; x. 38. 
Fie. 2.—The anterior extremity from the ventral surface to show the funnel- 
shaped opening of the proboscis extruded. yx. 3. ; 
Fig. 83.—Side view of the anterior end of the body. /. proboscis. x. 3. 
Fig. 4.—Ventral surface of the posterior end, showing, sc. the terminal opening 
of the sucker, mo. the opening of the male organs on a papilla, fo. the opening of the 
female organs at the base of the papilla anteriorly. x. 3. 
Puate 12. 
Vigs. 1—6.—A series of transverse sections (of which figure 1 is the most 
anterior) through the region where there is apparently a duct leading from the central 
cavity, containing ova, to the receptaculum; o'. central space containing ova; 
od. oviduct leading to uterus; od.’ the supposed duct which in figure 5 has apparently 
come in contact with the walls of the receptaculum, though no lumen can be clearly 
distinguished. There is an interval of two sections between those represented in 
figures 4 and 5; rs. receptaculum full of ripe ova; yk. the duct of the yelk gland 
cut in section; in figure 5-it is seen to join the oviduct. Drawn under Zeiss C. oc. 2. 
