48 RESEARCHES IN HELMINTHOLOOY AND PARASITOLOGY. 



Habitation. — Lungs of Rana halecina. 



Remarks. — Very distinct from Ascaris nigro-vaiosa, Zeder, which 

 is three times as large and possesses membranous appendages. The 

 largest female, with the oviducts distended with eggs of Ascaris 

 oitomclas, do not measure over i )^ lines. It is also not to be con- 

 founded with Angiostonia entomclas, Duj., which as a generic char- 

 acter possesses a corneous capsule within the head. 



DiSTOMUM, Retzius. 



3. Distomum Longuni, n. s — Body whitish, with the blackish 

 ovaries showing through the anterior two-thirds, subcylindrical, 

 compressed ; posteriorly subligulate, or spatulate, obtusely rounded ; 

 neck cylindrical. Oral acetabulum obliquely terminal, urceolate, 

 broader than the neck, 3-5ths of a line in diameter. Ventral ace- 

 tabulum a little smaller and from i^i to 2 lines behind the former; 

 orbicular, projecting % a line in diameter. Generative aperture 

 just anterior to the middle of the neck, or nearer the oral acetabulum. 



Length 15 lines to 3 inches ; breadth 2-5ths to 3-4ths of a line. 



Habitation. — Six individuals found in the mouth of Esox cstor, 

 Cleveland, Ohio. Received from Prof. S. F. Baird. 



Remarks. — This is a remarkable species of Distomum from the 

 very great relative length to the breadth. 



4. Distomum Terretico/te, Rud. Entoz. Syn., p. 102; Dujardin, 

 Hist. Nat. des Helm.; Diesing, Sj'st. Helm., p. 358. 



Body sub-cylindric, light flesh color, posteriorly rovmded. Ven- 

 tral acetabulum -V^'ths of a line behind the oral, V^d line in diam- 

 eter. Oral acetabulum, //4 th of a line. 



Length 8 lines ; breadth posteriorly V2 line, anteriorly ^id line. 



Habitation. — Stomach of Esox reticulatus. Lesueur. 



Remark. — The generative aperture is placed immediatel}' in ad- 

 vance of the ventral acetabulum. When the animal contracts, the 

 two acetabula are nearly brought into contact. 



5. Distomum Rctusum. — Duj. Hist. Nat. des Helm., p. 405; 

 Diesing, Syst. Helm., p. — . 



Body whitish, with yellowish brown from the ova ; oblong, sub- 

 linear, slightl}^ narrowed anteriorly ; posteriorly truncate, slightly 

 sinuous. Oral acetabulum larger than the ventral. Posterior re- 

 spiratory sinus very large. 



Length ^ to \]/z lines ; breadth \\ line. 



Hab. — Small intestine of Rana haleci^ia. 



6. Distomum Cygnoidcs. — Zeder, Nachtrag., p. 175; Dujardin, 

 Hist. Nat. des Helm., p. 396 ; Diesing, S5^st. Helm., p. 342. 



