100 [Oct. 



were deeply reflected upon the outside of the body, and the inner circle projected 

 obliquely outward and upward. The proboscis was clavate in form or cylindri- 

 cal and moderately dilated at its free end, and more so at its base. The follow- 

 ing six days no perceptible change was observable in the development of the 

 animal, and after this the eggs showed evident appearances of decay, and I gave 

 them no further attention. 



Tioo new species of Infusorial Eiitozoa. 

 By Joseph Leidy, M. D. 



1. Nyctotherus ovalis. Body translucent oval, posteriorly obtuse. Ante- 

 rior granular areola three sided. Posterior fissure passing downwards. 



Length 1-lOOth inch, breadth l-33d inch. 



Habitatioji. The intestinum tenue of the Blatta orientalis, occasionally in 

 considerable numbers. 



2. BoDO JuLiDis. Body translucent, faintly greenish, faintly granular with one 

 or two large round vacuoles and numerous minute ones ; form changing, usually 

 globular, oval, or pyriform ; caudae twice the length of the body, very active, 

 frequently twisted into a ring at the extremity. Diameter of body l-3000th of 

 an inch. 



Hahitation. The large intestine of Julus marginatus, in company with Nyc- 

 totherus velox, often in millions. 



Description of some Nematoid Entozoa infesting Insects^ 

 By Joseph Leidy, M. D. 



Genus Aorurus. Sub-genus Streptostoma. Proc. Acad. Nat. Sci. 1849 p. 

 230. 



1. Streptostoma gracile. 



Oxyuris Diesingii. Hammer schmidt. Isis von Oken J. 1838, S. 354, Taf. iv. 

 Fig. 6. 



Body attenuated from the middle anteriorly and posteriorly, white, translucent, 

 shining. Anterior annuli very broad and moveable upon one another. Oral 

 annulus short, truncate ; second annulus long, constricted in the middle. Tail 

 nearly one-third the length of the body, shining, straight or curved. Pharynx 

 short. Oesophagus consisting of two elongated, pyriform, muscular bulbs. Neck 

 of first oesophageal bulb dilated at commencement and middle ; neck of second, 

 long, narrow and cylindrical. Ventriculus largely dilated and oval at commence- 

 ment, afterward cylindrical. 



Length of body 1 line; breadth opposite ventricular dilatation l-136th inch; 

 just above anus l-300th inch; greatest do., l-107th in; length of tail l-40th 

 inch ; breadth at middle 1.1360th inch ; length of first pyriform bulb of oesopha- 

 gus l-150th inch ; breadthof neck of do. 1-llOOthinch; do.of body of do. l-400th 

 inch; length of second bulb l-214th inch; breadth of neck l-1300th inch ; do. of 

 body l-340th inch; do.of dilated commencement of ventriculus l-214th inch. do. 

 of cylindrical portion l-330th inch. 



Ova oval, l-300th inch long by l-625th inch broad. 



Habitation. Found in numbers of one to half a dozen in the small intestine of 

 our domestic cockroach, (Blatta orientalis.) This species was discovered by 



