46 A FAUNA WITHIN ANIMALS. II. 



Habitation. Pound within the large intestine of Julus marginatus, and less fre- 

 quently within the ventriculus. 



2. Streptostomum gracile, LEIDY. 



Proc. Acad. Nat. Soi., v., 100 ; ib. v., 285. 



SYN. Oxyuris Diesingii, Hamraerschmidt: Isis, 1838, 354, Taf. iv., Fig. 6. 



Oxyuris Blattce Orientalis, Hammerschmidt: Naturwissenschaftliche Abhandlungen von HAID- 



INGER, I. 284, Taf. x., Figs. 4, 7, 13-15. 

 Anguillula macrura, Diesing : Systema Helminthum, II. 134. 



(PLATE VII. Figs. 6, 7.) 



Female. Body cylindroid, attenuated from the middle anteriorly and posteriorly. 

 Anterior annuli very long and movable upon one another ; posterior annuli shorter 

 and not so distinct. Oral annulus short, simple ; second amiulus long, constricted in 

 the middle. Tail nearly one-third the length of the body, straight or curved, spi- 

 culate, shining. Mouth round, simple ; buccal organ elongated pyriform, with the 

 neck cylindroid, dilated at its commencement and middle, extending through ten 

 annuli ; gizzard with a narrow cylindroid neck and globular body, extending to the 

 eighteenth annulus; intestine cylindroid, very largely dilated oval at commence- 

 ment. 



Measurements. Length of body 1 line ; breadth opposite the ventricular dilata- 

 tion T |^ inch ; greatest do. T ^ T inch ; just above anus -gfa inch. Tail ^ inch 

 long by the laV^ mc h broad at middle. Buccal organ T |^ inch long ; gizzard 

 inch long. Ovum oval, -$%-$ inch long, ^ T inch broad. 



Habitation. Found within the intestinal canal of Blatta orientalis. 



5. DESCRIPTION OF THE GENUS AND SPECIES OF THELASTOMUM. 



THELASTOMlIltt, LEIDY. 



Body cylindroid, annuli moderately long. Oral annulus papilltcform. Mouth 

 small, circular, without lobes or other appendages; buccal organ long, cylindrical; 

 gizzard pyriform. Tail moderately long, spiculate. Penis consisting of a single 

 spiculum. 



1. Tlicla si <>iii 11 in attcmiatiiiii, LEIDY. 

 Proc. Acad. Nat. Sci., iv., 231 ; ib. v., 285. 



(PLATK VI. Fig. 4; VII. 1, 23. 



Female. Body cylindroid, translucent white, shining, attenuated anteriorly from 

 the commencement of the intestine, divided into from 140 to 160 annulations. 

 Oral annulus minute, papillaeform ; second annulus small, compressed oval. Tail 

 very straight, or slightly curved, slender, spiculate, acute. Mouth small, simple ; 

 its passage extending through two and a half annuli ; buccal organ and gizzard 

 extending through 55 annulations, the former, very long, cylindrical, rounded at 



