288 University of California Publications in Zoology [Vol.19 



thickness but little less than the thickness of the body. In immature 

 specimens (fig. 5, t.) they are much smaller and behind the middle of 

 the body. 



The ovary (figs. 1 and 3, ov.) is spherical and has about two-thirds 

 the diameter of one of the testes. It is located to the left of the ventral 

 sucker and may overlap this organ dorsally. The relations of the 

 female ducts are shown in figure 3. The oviduct (fig. 3, ovd.) leaves 

 the inner margin of the ovary near its posterior end. It runs but a 

 short distance before receiving the duct from the small pear-shaped 

 seminal receptacle (s.r.). Laurer's canal (L.c.) opens into the oviduct 

 just beyond the duct of the seminal receptacle and passes dorsad and 

 posteriad between the testes to open on the dorsal surface. The 

 oviduct further receives the common vitelline duct from the small 

 vitelline reservoir just before it enters Mehlis' gland {M.g.) to change 

 into the ootype (oat.). The beginning of the uteiiis («.) curves 

 forward for a short distance and then turns back, passing between 

 the testes dorsad. The coils of the uterus fill the whole posterior body 

 region and it was impossible to follow their exact course. The terminal 

 portion of the uterus (fig. 2, u.) immerges from the posterior coils 

 near the ventral surface of the body and passes forward between the 

 testes, changing into the metraterm (fig. 2, met.) just ventrad of the 

 posterior end of the cirrus sac. The metraterm is thick-walled and 

 runs parallel to the cirrus sac to open at the common genital pore 

 (fig. 2). 



The vitellaria (fig. 1, vit.) are made up of small irregular follicles 

 which are not arranged in definite groups. The vitellaria are located 

 along each side of the body both dorsally and ventrally and extend 

 from the region of the oral sucker back to the posterior margin of the 

 testes. Dorsally or ventrally they may extend nearly to the mid line 

 of the body. The vitelline ducts (figs. 1 and 3, v.d.) run transversely 

 near the dorsal surface and join the small vitelline reservoir. 



The eggs of Margcana californicnsis are brownish in color and have 

 shells of medium thickness. The operculum is well defined and each 

 egg contains a fully developed miracidum. Measurements of twenty- 

 five normal eggs from two different specimens showed a range of 

 variation from 46,u. X 19/" to 56yu X 26/x. The size most frequently 

 found which represents about the average was 51/x X 24/*. 



The excretory system of Margeana calif orwiensis (fig. 5) was 

 worked out completely from living material. The excretory pore 

 (fig. 5, ex.p.) is located on the ventral surface near the posterior end. 



