48 A FAUNA WITHIN ANIMALS. H. 



Hahifatton.— 'Found within the ventriculus and large intestine of PoJi/desjmos 

 virginiensis. 



4. Tlielnstoiniiiu robiistiiiu, 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 l)ody. 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 ^-^ of an inch ; at middle g\ of an inch ; just above the anus y\ of an 

 inch. Length of tail ^V ^^ ^^^ "^*^^^ 5 breadth at middle xoVo ^^ ^^'^ inch. Buccal 

 organ ^V of ^" i^ich long ; gizzard j-^-g- of an inch. Ovum 3^ „ of an inch long by 

 ^^^ of an inch broad. 



Hahilation. — Litestinal canal of the larva of a lamellicorn coleopterous insect. 



5. Thelastomuiii forevicaudaftiiu, Leidy. 



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 y\ of an inch; at middle -^^ of an inch; just above anus yi^ of an inch. 

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

 ■^\-^ of an inch long. Ovum oval, ^\^ of an inch long. 



Habitation. — Intestine of the larva of Scarabceus relictus. 



6. Thelasfoimiiu gracile, Leidy. 



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



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



X. Figs. 21-25. 

 Anguillula gracilis, Diesing: Sjst. Ilelm. II. 133. 



7. Tlielastoiuiiiii depresisiiiin, Leidy. 



Oxynris depressa, Hanimerschmidt: Isis, 1838, 354, Tab. IV. d. e. 



Oxyuris dilaiata, Ilammersclimidt: Naturwis. Abhandl. v. IIaid. I. 287, Tab. X. Figs. 26, 27. 



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



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



8. Thclastoiiiiiiii laticolle, Leidy. 



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



Oxyuris laticollis, Ilammersehmidt: Naturwis. Abhandl. v. IIaid. I. 288, Tab. X. Figs. 28-34. 

 Anguillula laticollis, Diesing : Syst. Ilelm. II. 134. 



