The Sexual Phases of Myzostoma. 
299 
'55. Van Ben e den, P. J., Sur les organes sexuels des Huìtres. in: Compt. 
Rend. Tome 40 1855 pag. 547—548. 
'78. Vejdovsky, Franz, Beiträge zur Kenntnis der Tomopteriden. in: Zeit. 
Wiss. Z. 31. Bd. 1878 pag. 81—100 Taf. 6, 7. 
'84. System und Morphologie der Oligochaeten. Prag 1884. 
'92. Watasé, Sho, On the Phenomena of Sex -Differentiation. in: Jonrn. 
Morph. Boston Vol. 6 1892 pag. 481—493. 
'85. Weismann, Aug., Die Kontinuität des Keimplasmas als Grundlage einer 
Theorie der Vererbung. Jena 1885. 
'94. Wheeler, ^Y. M., Protandric Hermaphroditism in Myzostoma. in: Z. An- 
zeiger 17. Jahrg. 1894 pag. 177—182. 
'75. Willemoes-Suhm, R. v.. Von der Challenger-Expedition. Briefe an 
C. Th. V. Siebold. 3. in: Zeit. Wiss. Z. 25. Bd. 1875 pag. 25—46. 
'92. Wirén, A., Studien über die Solenogastres. 2. in: Kongl. Svenska Akad. 
Handl. 25. Bd. N. 6 1892. 
'91. Zur Strassen, Otto, Über Filaria rigidia. in: Z. Anzeiger 14. Jahrg. 
1891 pag. 437—439. 
Explanation of the Plates 10 — 12. 
Refe r enee Letters. 
ac.n nuclei of accessory cells. 
ac.o oral sucker. 
acv ventral sucker. 
am parasitic Amoeba. 
an anus. 
c food-particles. 
cl cloaca. 
eoe coelom (body-cavity). 
er cirrus. 
ex.p excretory pore. 
/ fissures in the ovary. 
gd gonad. 
gr deeply staining granules. 
int intestine. 
int.ep intestinal epithelium. 
intr intestinal ramification. 
juv young Myzostome. 
l.l lateral edges of the body. 
mm manubrium. 
ms muscles. 
neph nephridium. 
n.gl nuclei of gland-like cells. 
n.n zone of small nuclei. 
nv ventral ganglion. 
o Ovum. 
o.a Ovum just attached .to peritoneal 
epithelium. 
o.m Ovum migrating through the body- 
cavity. 
oog oogonia dividing. 
o.ut orifice of the uterus. 
oü ovary. 
ov.a anterior ovary. 
ov.p posterior ovary. 
p parapodium. 
par parenchyma. 
pen penis. 
p.ep peritoneal epithelium. 
pg pigment. 
ph pliarynx. 
pst boss of the segmental sac of J/. 
piatì/pus. 
q pharyngeal tissue drawn into the ven- 
tral sucker oi Distoma myzostomatls. 
r ring enclosing the boss of the seg- 
mental sac. 
sep septum. 
s.m smooth muscle cells. 
