1919] 



Cort: A New Distome from Emm aurora 



289 



From it the muscular club-shaped bladder (&.) extends almost up 

 to the testes. In the immature specimens the anterior end of the 

 bladder extends to about the same position but the bladder is very 

 much shorter (fig. 4, &.). The anterior end of the bladder is somewhat 

 widened to receive the common collecting tubes (fig. 5, c.c.t.) on each 

 side, but there is no trace of bifurcation. The filling and contraction 

 of the bladder could be followed in the immature specimens, in which 



Fig. 3. Connections of the ducts of the female reproductive system of Mar- 

 geana calif orniensis ; L.c, Laurer 's canal; m.. Mehlis ' gland; o.o.t., ootyp; ov., 

 ovary; ovd., oviduct; g.r., seminal receptacle; ».. uterus; v.d., vitelline duct. 



it was not obscured by the folds of the uterus. Starting with the 

 bladder entirely contracted and empty for its whole length, there can 

 first be noticed a dilation of the common collecting tubes near the 

 points where they enter the anterior end of the bladder. The anterior 

 end of the bladder then fills with liquid and finally becomes much 

 distended. The muscular contraction of the anterior end then drives 

 the liquid down into the posterior bulb, which becomes distended. 

 At this time the whole bladder contains liquid. Then the anterior 

 half of the bladder becomes entirely contracted, further distending 

 the posterior bulb. With the contraction of the posterior bulb and 

 the expulsion of the liquid contents the whole bladder becomes empty. 



