52 TREMATODES OF THE PACIFIC NORTHWEST 



Host: Clemniys vmr)norata Ore. Thatcher, 1954 



Additional hosts are Hsted by Wharton (1940). 



Morphology : See any of the authors of synonyms above for descriptions and 

 figures. 



Biology : Xiphidiocercariae develop in Physella intcgra, encyst in tadpoles, and 

 develop to maturity in Chrysonys picta. They do not mature in Thainnophis 

 sp., but do live for several weeks (McMullen, 1934). 



Zeugorchis syntomentera Sumwalt, 1926 



Synonyms: Pscudorcnifer syntomentera (Sumwalt, 1926) Allison & Holl, 1937 

 Paralcchriorchis syntomentera (Sumwalt, 1926) Bvrd and Denton, 

 1938 



Hosts : ThamnopJiis sirtalis Wash. Sumwalt, 1926 



ThainnopJis ordinoides Wash. Sumwalt, 1926 



No other hosts are known. 



Taxonomy : This species was transferred to Pseiidorenifer by Allison and Holl 

 (1937) and then to Paralechriorchis by Byrd and Denton (1938). Yamaguti 

 (1958) rejected both these proposals and retained Zeugorchis. Skrjabin and 

 Antipin (1957) accepted the genus Paralechriorchis. 



Morphology : Adult and larval stages were described and figured by Ingles 

 (1933) and Skrjabin and Antipin (1957). 



Biology : Xiphidiocercariae develop in Physa gyrina, enter tadpoles of Rana 

 aurora or Hyla regilla, which are in turn eaten by snakes (Ingles, 1933). 



Family PSILOSTOMIDAE 



Sphaeridiotrema globulus (Rudolphi, 1819) Odhner, 1913 



Synonym : Distoma globulus Rudolphi, 1819 



Host: Birds Ore. Dikmans, 1945 



Hosts from other areas in Yamaguti (1958). 



Morphology: Described and figured by Skrjabin (1947c) and Dawes (1946). 



Biology: Szidat (1937) showed that cercariae develop in Bythinia tentaculata, 

 encyst on the inside of the shell of this snail, and develop to maturitj- in 

 Anas bosclias. Price (1934) showed that this parasite caused a fatal ulcera- 

 tion of the intestine in Marila affinis. 



Pseudopsilostoma ondatrae (Price, 1931) Yamaguti, 1958 



Synonyms : Psilostomum ondatrae Price, 1931 



Ribeiroia ondatrae (Price, 1931) Price, 1942 



Host: Larus calif ornicus Ore. Price, 1931c 



This form has also been reported from tlie muskrat in other parts of North 

 America by Price (1931c). 



