54 TREMATODES OF THE PACIFIC NORTHWEST 



Biology : Furcocercous cercariae develop in Physa ampullacea and penetrate the 

 definitive host. The cercariae produce cercarial dermatitis in man (Macy, 

 Moore, and Price, 1955). 



Trichobilharzia physellae (Talbot, 1936) McMullen and Beaver, 1945 



Synonyms : Cercaria physellae Talbot, 1936 



Pseudohilharzia quequeduale McLeod, 1937 



Hosts : Physa ampullacea Ore. Macy & Moore, 1953 



Physa gyrina Idaho Schell, 1959 



Additional hosts have been reported from Manitoba (McLeod, 1937; AlcLeod 

 and Little, 1942) and Michigan (McMullen and Beaver, 1945). 



Biology : The life history has been experimentally w^orked out by McLeod and 

 Little (1942) and McMullen and Beaver (1945). Furcocercous cercariae 

 develop in species of Physa and mature in various birds. When the cercariae 

 penetrate man they cause cercarial dermatitis. 



Gigantobilharzia huronsis Najim, 1950 



Host: Physa gyrina Idaho Schell, 1959 



Additional hosts were reported by Najim (1950). Woodhead (1955) 

 described the miracidium. 



Biology: Najim (1950) reported that the cercariae from snails produced adults 

 in chicks and canaries. His description was in abstract only. 



Schistosomatium douthitti (Cort, 1915) Price, 1931 



SjTionym: Cercaria douthitti Cort, 1915 

 Host: Lymnaea palustris 



nuttalliana Idaho Schell, 1959 



Additional hosts have been reported from Illinois (Cort, 1914, 1915b), 

 Michigan (Cort, 1918, 1936; Price. 1931a), Wisconsin (Brackett, 1940), Minne- 

 sota (Penner, 1938). 



Biology: The life history was worked out by Price (1931a) and involved 

 furcocercous cercariae developing in the snail hosts and becoming adults in 

 several mammals. Kagan, Short, and Nez (1954) discussed the laboratory 

 propagation of the trematode and had an extensive bibliography. The 

 cercariae cause dermatitis in man. 



Cercaria columbiensis Edwards and Jansch, 1955 



Host: Physa conformis B.C. Edwards & Jansch, 1955 



This form has not been found since and nothing is known of the biology, 

 except that it causes dermatitis. 



Cercaria tuckerensis Miller, 1927 



Host: Planorhis sp. Wash. H. M. Miller, 1927 



This dermatitis-producing cercaria has not been reported since. 



