II. A FAUNA WITHIN ANIMALS. 47 



the extremities; the latter pyriform, with a short neck, and narrower than the 

 buccal organ ; intestine cylindrical, dilated, subcordiform at commencement; rectum 

 inverted pyriform. Generative aperture 42 annulations anterior to the anal. 



Measurements. Length of body -fc to \ of an inch ; breadth at middle -^ of an 

 inch. Tail ^ of an inch in length by yoVg- of an inch broad at middle. Buccal 

 organ i line long by ^|^ of an inch broad ; gizzard T | ? of an inch long. 



Ova 3^3- of an inch long by %%-$ of an inch broad. 



Habitation. Found with Streptostomum agile, within the large intestine of Julus 

 marginatus. 



2. Thelastomum appcndieulatum, LEIDY. 



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



SYN. Oxyuris Blattce orientalis, Hammerschmidt : Naturwiss. Abhandl. von HAIDINGER, I. 284, Taf. x. 

 Figs. 10-12 (male, 8, 9, 20?). 



(PLATE VII. Fig. 3.) 



Female. Body cylindroid, translucent white, attenuated anteriorly and poste- 

 riorly ; divided into from 80 to 90 annulations. Oral and second annulus, as in the 

 preceding species ; terminal annulus with two short spines projecting backward. 

 Tail straight, spiculate, one-fourth the length of the body. Mouth small, simple ; 

 its passage extending to the third annulus ; buccal organ and gizzard extending to 

 the thirtieth annulation ; the former long, cylindrical ; the latter pyriform ; com- 

 mencement of the intestine broad, cordiform, becoming cylindroid and sending off 

 a large diverticulum. Generative aperture 26 annulations anterior to the anal. 



Measurements. Length of body 1 line to -^ of an inch ; breadth at commence- 

 ment of the ventriculus T -J- T of an inch ; at middle -^ of an inch ; at anus -j^ of 

 an inch. Tail i of a line long by | of an inch broad at middle. Buccal organ 

 5*5- of an inch long ; gizzard ^^ of an inch long. Ovum semi-oval, ^| 7 of an inch 

 in length by ^|^ of an inch broad. 



Habitation. Found with Streptostomum gracile in the intestinal canal of Blatta 

 orientalis. 



3. Thelastomnm labiatnm, LEIDY. 



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



(PLATE VII. Fig. 13.) 



Female. Body cylindroid, transparent, anteriorly and posteriorly attenuated, 

 divided into 140 annulations, of which the anterior are very strongly marked. Oral 

 annulus inflated, six-lobed at the margin ; second annulus constricted anteriorly. 

 Tail straight, spiculate, very nearly half the length of the body. Mouth round, 

 extending through one and a half annuli ; buccal organ and gizzard extending to 

 the fortieth annulus ; the former cylindroid ; the latter robust ; intestine at com- 

 mencement subcordiform. 



Measurements. Length J of a line to ^ of an inch ; breadth ^^ u of an inch. 

 Length of tail ^ of an inch. Buccal organ T 7 of an inch ; gizzard 7 ^ of an 

 inch. Ovum oval, 5 T of an inch long by -^fa of an inch broad. 



