RESEARCHES IN HELMINTHOLOGY AND PARASITOLOGY. 5 1 



Hab. — Found in numbers from one to four in the intestine of 

 larvae of a large lamellicorn insect, found by ray friend Mr. S. Powell 

 in earth mould near Philadelphia. 



Greg.'^rina, Dufour. 



12. Gregari)ia. — Body white, cylindro-fusiforra. Superior division 

 presenting four sides of a hexahedron, subacute. Nuclear body of 

 inferior division transparent, globular or elliptical, containing several 

 coarse granules. 



Length from i -66th to i '4 lines; head i -400th inch to i-i33d 

 inch long by i-285th inch to i-iiith inch broad. Anterior portion 

 of inferior division i -200th inch to i-S6th inch broad ; posterior 

 portion i -666th inch to i -250th inch broad. lyongitudinal lines of 

 inferior division more distinct than those of the upper division, 

 I -8000th inch apart. 



Hab. — Found in the same insect as the preceding. 



RcDiark. — Since the discovery* of the beautiful parallel, longi- 

 tudinal line of the inferior division of the body of Grcgahna after a 

 careful examination I have come to the conclusion that the}' also 

 exist upon the superior division. 



13. Astacobdella PJiiladelphica, n. s. — ^Body whitish, translucent, 

 sides nearl}' parallel, a little broader posteriorly, 16 alternately broad 

 and narrow segments exclusive of head and posterior end. Head 

 campanulate, terminated by a circular or elliptical crenated lip 

 fringed with very minute stiff hairs, i -2000th inch long. Acetabu- 

 lum circular, i-6th to /4 th line in diameter. Mouth elliptical. 

 Dental plates brown, nearly equal, forming an isosceles triangle, 

 with the base longest and attached. Apex of superior plate ending 

 in a sharp conical point, with .several very minute denticulations on 

 each side. Apex of inferior plate bifurcated into two points, with 

 two minute denticulations on each side. Stomach capacious, nearlj- 

 filling the anterior, 8 alternately broad and narrow segments poste- 

 rior to the head. Anus dor.sal, i-5th of aline from the acetabulum. 

 Generative aperture ventral, anterior to the anal aperture. 



Length i to 4 lines ; breadth i-6th to Y^ line. Head i-6th to yi 

 line long. Ovum attached by a pedicle, with an operculum pointed 

 at summit. From base of attachment to point of opercle, i-5th line. 

 Length of body of ovum i-6th line ; breadth i-8th line. 



Hab. — Found frequently in numbers from one to several dozen 



*Proc. Acad. Nat. Sci., vol. 4, p. 232, 1849. 



