896 J- Stafford, 



Frösche, Stuttgart, 1894. There the autlior noticed certain variations, 

 particularly of the structure of the skin, and in his Weitere Beiträge 

 zur Kenntniss der Trematoden - Fauna Aegyptens, in: Zool. Jahrb. 

 V. 12, Anat. 1899, he makes 3 species: Haematoleocims variegatiis, 

 H. simüis, and H. asper, with differences chiefly in the skin, the 

 size and position of the genital organs, and the size and shape of 

 the egg. 



At intervals during the last two years I have examined our 

 Canadian Amphibia for the Distome in question and have studied, 

 in one way or auother, many hundreds of its representatives taken 

 from their lungs. It is my Intention to announce here my results 

 so far as segregation of species is concerned. 



For some time after entering upon this study, all the worms 

 presented a sameness of appearance which was sufficiently well 

 expressed in the word 'variegaUim'. But after gaining some insight 

 into the distribution of black, brown and gray it became gradually 

 apparent that the variegated look of the animals — due chiefly to 

 the coils and foldings of the long uterus, distended with its countless 

 brown-shelled eggs — was accompanied by certain regularly recurring 

 characters. All the individuals I have yet come upon fall into one 

 or auother of five different types — none of which agree with the 

 European forms as described by Looss. Notwithstanding numberless 

 slight variations, these five types appear to be constant in the 

 possession of certain characters which may, with tolerable readiness, 

 be used to distinguish them and which we shall, consequently, regard 

 as specific. To distinguish one of the members of this group from 

 any other species is not a difficult matter; what we have to do is 

 to show that there are sufflcient differences to distinguish the members 

 from one another. For the present, I shall briefly name them No. 1, 

 2, 3, 4, 5; and, since they are very closely related, I can deal with 

 them most concisely by including a number of considerations under 

 the present heading ,General' and afterwards recount their chief 

 characteristics under the heading ,Specific'. 



Occurrence. I have examined eight species of our Tailless 

 Batrachia, belonging to the genera Bufo, Hyla and Bana, but only 

 the Toad, the Bull Frog and the Green Frog in large numbers. 

 The Worms occur in the lungs, attached by their mouth suckers and 

 insinuated between the spongy fibres. 



Extern al Features. Size and Shape are not characters 

 of Wide and safe application, since the animals reach sexual maturity 



