RESEARCHES IN HELMINTHOLOGY AND PARASITOLOGY. 93 

 PON'fONEMA, LdlDY. 



Body capillary, narrowing toward the extremities. Head continu- 

 ous with the body, truncated and surmounted with angular papillse 

 cirrated. Eyes none. Tail obtuse. Generative aperture ventral, 

 near the middle of the body. CEsophagus long, cylindro-clavate ; 

 gizzard none, intestine straight, capacious ; anus ventral and pos- 

 terior. 



96. Po}itonci)ia Wxcillaiiiiii , Leidy. Jour. A. N. S., 2d .ser. , iii, 

 144. Body cylindroid, anteriorly with longitudinal rows of short 

 cirra in addition to tho.se of the head ; posteriorly incurved ; tail 

 short, thick, conical, obtuse. Length to 9 lines, breadth to one- 

 fifth of a line. 



Found on the seashore of Rhode Island, beneath stones, between 

 tides. 



97. Ponto)iciiia Marinnni, L,eidy. Jour. A. N. S., 2d ser., iii, 144. 

 Body cylindroid ; head convex ; mouth surrounded with angular 

 papillae. Cirra 4, at the side of the head. Tail long, narrow, con- 

 ical, obtuse. Length to 3 lines. 



Found at the bottom of a sound on the coast of New Jersey. 



POTAMONEM.\, LEIDV. 



Body filiform, narrowing towards the extremities. Head contin- 

 uous with the body, slightly dilated, obtuse. Mouth large, infundi- 

 buliform, unarmed ; cesophagus narrow, flexuous, membranous, 

 gradually expanding into a capacious, straight, cylindrical intestine ; 

 anus none ? or exceedingly indistinct. Caudal extremity obtuse. 

 Generative aperture of the female near the middle of the body. 



98. Potaiiioncnia NitidiDu, Leidy. Body cylindroid, most nar- 

 rowed anteriorly. Head without appendages. Caudal extremity 

 broad, obtusely conical. Length 5 lines, breadth one-fifth of a line. 



An active wriggling, glistening white worm, found among beds 

 of VaUsneria aiiu'ricaua growing in the river vSchuylkill, near Phil- 

 adelphia. 



Nem.a., Leidv. 



Body ascaridiform. Head without appendages. Mouth unarmed, 

 large, infundibuliform, oesophagus tubular, membranous, expand- 

 ing into a simple straight intestine ; anus ventral. Tail conical, 

 acute, recurved. Generative aperture near the middle of the bod}'. 



99. Xcma Vaa7a7is,'L,eidy. Body white, glistening. Length ij^ 

 millimeters, breadth .050 mm. Tail .115 mm. long. 



