94 ZOOLOGY 
system.  Hermaphrodite ; follicular testis and paired 
ovaries. Marine. Frequently with brown or green 
parasitic algae. Convoluta, Proporus. 
Tribe 2. Rhabdocoela.—Stomach distinct from parenchyma, 
and simple. Pharynx complicated. Compact testes and 
ovary, the latter divided into a germarium and vitel- 
larium.  Otocysts rare. Marine, freshwater, and land 
forms. 
Prorhynchus inhabits damp earth. The MEso- 
STOMIDA and VoRTICIDA are the chief freshwater familes ; 
the latter includes two parasitic genera—Grafilla found 
in Gastropods, and Anoplodium in Holothurians. 
Fic. 65.—Plan of an Alloiocoelous Turbellarian. 
After Von Graff. 
. Bursa copulatrix. 
. Brain. 
Eye. 
. Germarium. 
. Intestine. 
. Longitudinal nerve trunk. 
. Mouth. 
. Pharynx. 
. Testis. 
. Yolk gland. 
. Vesicula seminis. 
. Oviduct. 
. Chitinous copulatory organs. 
. Common sexual aperture. 
Hee 
SNH ODOANAMNPEWNHH 
Bg 
+0 
Tribe 3. Alloiocoela—Stomach lobed or irregular, pharynx 
present, testes follicular.  Otocysts occur in the Jamily 
Monotida. 
All marine, except Plagiostoma Lemani, which in- 
habits the deep water of certain Alpine lakes. 
