Nachdruck verholen. 

 Ubersetsungsrecht vorbehalten. 



Observations on Loxogenes arcanum Nickerson, 

 a Trematode parasite of frogs in Minnesota. 



By 



Henry Leslie Osboru. 



(Contributed from the Biological Laboratory of Haraline University, 

 Saint Paul, Minn., U.S.A.) 



With Plates 24 and 2 Figures in the text. 



A brief account of certain points in the anatomy of Loxogenes 

 arcanum Nickerson, was published by the writer in the Zoologischer 

 Anzeiger for May 1912, in which the occurrence of this species in 

 the frogs of Minnesota was noted for the first time and some items 

 in regard to the structure of the worm were reported. The species 

 is exceedingly rare in this state having been found in only three 

 cases, and has been encountered in only two other American locali- 

 ties: once in Ontario by Stafford (1900), encysted in the liver of 

 the bull-frog, Rana catesbiana; and again by Nickerson (1900), in 

 the frogs of Massachusetts, encysted on the wall of the small in- 

 testine near the pylorus. Nickerson stated that it was not found 

 by him in the frogs of Minnesota. So very little has been placed 

 on record in regard to this worm that it seems desirable to give 

 an account of the observations which have been made on its habitat 

 and the behavior of the living worm as well as a description of 

 certain histological matters of somewhat unusual interest. 



