48 A FAUNA WITHIN ANIMALS. II. 



Habitation. — Found within the ventriculus and large intestine of Pblydesmm 

 virginiensis. 



4. Thelastomum robustnin, Leidy. 



Proc. Acad. Nat. Sci., v., 101 ; ib. 285. 



Female. — Body white, cylindrical, narrowed anteriorly and posteriorly, divided 

 into from 200 to 220 annulations. Oral annulus simple. Tail straight, little more 

 than one-eighth the length of the body. Mouth round, simple ; buccal organ and 

 gizzard extending through forty annulations ; intestine largely dilated oval at 

 commencement. Generative aperture 70 annulations anterior to the anal. 



Measurements. — Length of body 2 lines ; breadth at the commencement of the 

 intestine ^V of an inch ; at middle ^^ of an inch ; just above the anus yV of an 

 inch. Length of tail ^^ of an inch; breadth at middle i-^Vo' ^^ ^^ inch. Buccal 

 organ -^ of an inch long ; gizzard j^-g- of an inch. Ovum -^^-^ of an inch long by 

 ^^^ of an inch broad. 



Habitation. — Intestinal canal of the larva of a lamellicorn coleopterous insect. 



5. Thelastommn brevicaudatum, Leidt. 



Proc. Acad. Nat. Sci., v., 208; ib. 285. 



Female. — Body cylindroid, anteriorly rapidly narrowing from the commencement 

 of the intestine, posteriorly abruptly rounded ; with a very short spiculate tail. 



Measurements. — Length of body to 2 lines ; breadth at commencement of intes- 

 tine yV of an inch; at middle -^ of an inch; just above anus ^^^ of an inch. 

 Length of tail from anus -^^-^ of an inch. Buccal organ -^^ of an inch long ; gizzard 

 2^77 of an inch long. Ovum oval, t^\-^ of an inch long. 



Habitation. — Intestine of the larva of Scarabceus relictus. 



6. Thelastomum gracile, Leidy. 



Proc. Acad. Nat. Sci., t., 285. 



Oxyuris gracilis, Hammerschmidt : Isis, 1838, 353, Tab. IV. c-f ; Naturwis. Abhandl. v. Haid. I. 287, Tab. 



X. Figs. 21-25. 

 AnguiUula gracilis, Diesing: Sjst. Helm. II. 133. 



7. Thelastomuiu depressum, Leidy. 



Oxyuris depressa, Hammerschmidt : Isis, 1838, 354, Tab. IV. d. e. 



Oxyuris dilatata, Hammerschmidt: Naturwis. Abhandl. v. Haid. I. 287, Tab. X. Figs. 26, 27. 



Thelastoma dUalatum, Leidy: Proc. Acad. Nat. Sci., v., 285. 



AnguiUula depressa, Diesing: Syst. Helm. II. 133. 



8. Thelastomum laticoUe, Leidy. 

 Proc. Acad. Nat. Sci., v., 285. 



Oxyuris laticollis, Hammerschmidt: Naturwis. Abhandl. t. Haid. I. 288, Tab. X. Figs. 28-34. 

 AnguiUula laticollis, Diesing: Syst. Helm. II. 134. 



