68 ILLINOIS BIOLOGICAL MONOGRAPHS [286 



since it is recorded in the same paper. Stafford, however, has failed to note 

 that Leidy recorded also in this same paper Distomum variegatum from the 

 lungs of Rana pipiens which he also describes in the same "earlier number" 

 in which he describes Distomum retusum. Hence Haematoloechus is ruled 

 out as well. From the habitat of these worms the writer suspects that it 

 may possibly be a larval stage of a species of Clinostomum. The descrip- 

 tion is so meager that it is impossible to place it in any definite manner. 



MONOSTOMUM SPATULATUM Leidy 1858 



Syn: Monostomum spathulatum Diesing 1859 



The following description given by Leidy includes the only available 

 data. "Body flat, oblong ovate, narrowing anteriorly, obtuse posteriorly, 

 color white, with brown tortuous lines indicating the course of the oviduct. 

 Mouth acetabuliform, circular. Testes three, alternating on each side 

 posteriorly with the oviduct. Ovaries on each side finely lobulated. 

 Generative aperture small a short distance behind the mouth. Penis 

 undistinguishable. Length 3-4 lines: breadth ^ line. 



Habitat: Gall-bladder. Host: Fish species unknown 



Locality: Eastern U. S. Collector: Jeffries Wyman 



MONOSTOMUM AFFINE Leidy 1858 

 Syn: Notocotyle(?)qffine Barker 1916 



Leidy described this species as follows: "Body spatulate narrowest 

 anteriorly, flat; posterior end obtuse, with an excretory orifice communi- 

 cating with a well marked canal traceable as far forwaid as the commence- 

 ment of the oviduct. Mouth round, oral acetabulum small, followed by 

 a smaller pharyngeal bulb. Intestine simple, traceable on each side to 

 the posterior end of the body. Testes four, posterior to the position of the 

 distended oviducts. Ovaries finely lobulated, situated on each side exter- 

 nal to the position of the intestine; oviduct transversely tortuous and dis- 

 tended with brown ova. Penis ensheathed, long, tortuous, echinate. 

 Generative aperture small, acetabuliform. Ova oval and prolonged at one 

 pole, or sub-pyriform. Length of body 6}4 lines; breadth 1 line." 



"Four specimens were obtained by Dr. J. N. Corse from the bile-ducts 

 and gall-bladder of the muskrat (Fiber zibethicus). Closely allied to M. 

 hippocrepis Diesing, but has no trace of the horse-shoe like collar to the 

 head." 



As is stated previously in this work the suggestion of Barker appears 

 to be a misfit on the basis of the pharynx, the echinate penis and the 

 undivided excretory canal which Leidy says is traceable as far forward as 



