S7J LIFE HISTORY OF T REM ATODES— FAUST 57 



DESCRIPTION OF THE TREMATODES INFECTING MOLLUSKS 

 OF THE BITTER ROOT VALLEY 



INTRODUCTION 



On account of the biological isolation of the Bitter Root Valley, it is little 

 wonder that it contributes new species of trematodes. The fourteen species 

 of trematodes found in the valley are not thot to comprise the entire trematode 

 fauna of the region, but are the representative species for the year and season 

 when the study was made. Of the fourteen species found in the Bitter Root 

 River, two are larval Monostomata, two are Holostomata, and the remaining 

 ten are Distomata. In addition to these, a larval holostome, Tetracotyle 

 pipientis nov. spec, from the vicinity of Chicago, Illinois, is included in the 

 study for the sake of comparison. 



Previous to the writers' preliminary report (Faust 1917) the following 

 larval trematodes have been described for North America. 

 Monostomata Distomata 



Cercaria hyalocatida Haldemann 1842 Cercaria polyadena Cort 1914 



Glenocercaria liicania Leidy 1877 Cercaria hemilophura Cort 1914 



Cercaria urbanensis Cort 1914 Cercaria trigonura Cort 1914 



Amphistomata Cercaria trivohis Cort 1914 



Cercaria inhabilis Cort 1914 Cercaria rubra Cort 1914 



Cercaria diastropha Cort 1914 Cercaria douthitti Cort 1914 



Cercaria gorgonocephala Ward 1916 Cercaria wrightii Ward 1916 



Distomata Cercaria anchoroides Ward 1916 



Cercaria agilis Leidy 1858 Cercaria marcianae La Rue 1917 



Rhopalocerca tardigrada Leidy 1858 (Really a Distomulum) 



Gymnocephala ascoidea Leidy 1877 Cercaria vergrandis La Rue 1917 



Cercaria platyura Leidy 1890 (Really a Distomulum) . 



Cercaria reflexae Cort 1914 Holostomata 



Cercaria megalura Cort 1914 Diplostomulum cuticula (v. Nordmann 1832) 



Cercaria leptacantha Cort 1914 Diplostomulum grande (Diesing 1850) 



Cercaria caryi Cort 1914 Diplostomulum volvens (v. Nordmann 1832) 



Cercaria isocotylea Cort 1914 Tetracotyle typica (Diesing 1858) 



Cercaria brevicaeca Cort 1914 Diplostomulum parmdum (Stafford 1904) 



Cercariaetim 



Cercariaeum helicis (Leidy 1847) Later recorded by Leidy as C. vagans (1850). 



In addition, there is the doubtful form, Cercaria bilineata Haldemann 1840. 



According to Stiles and Hassall (1908:157), Leidy is credited with the 

 record of a species, Diplostomulum rhachiaeum (Henle). Investigation of the 

 literature shows this to be an error, owing to the confusion of the names 

 Leidy and Leydig. Fr. Leydig described the species D. rhachiaeum for Europe 

 in 1853 (Leydig, 1853:383). 



Of the thirty-two forms listed, it is doubtful if any except those described 

 by Cort (1914), Ward (1916) and LaRue (1917) could be recognized by their 

 descriptions, since in the majority of cases the data are so indefinite as to leave 

 the systematist a wide range of choice in determining the species. An excellent 



