RESEARCHES IN HELMINTHOLOGY AND PARASITOLOGY. 69 



Body cylindroid, colorless, transparent ; anteriorly rounded, ob- 

 tuse ; posteriorly spreading into a cordiforni disk for attachment. 

 Disk retractile ; when retracted, the body becoming dilated oval in 

 the middle and the posterior part doubly intussu^cepted. 



Length i-iooth inch ; breadth i-ioooth inch. 



Habitation . — Parasitic within the intestine of Sty/aria fossularis. 



Remarks. — From the translucency of the last-mentioned worm, its 

 parasite may be seen within the intestine attached to the mucous 

 membrane by means of its posterior cordiform disk. While attached 

 it aflternately retracts its body with a jerk, and then lengthens itself ; 

 in the former movement the posterior third of the body becoming 

 doubly intussuscepted, so as to have the appearance of a double articu- 

 lation. When detached the same movement takes place, but in that 

 of retraction the cordiform disk is entirely drawn within the animal's 

 bod3\ More details of this curious parasite I did not obtain, for 

 although I saw three, and removed them from the intestine of the 

 Stylaria, yet their movements were so active I could not study them 

 to advantage, and to quiet them I tried a minute portion of the vapour 

 of chloroform, which in.stantly killed them, but at the same moment 

 they underwent total destruction. Since then I have not been able 

 to examine others. 



Gregarina, Dufour. 



I. Gregarina Searabei relieti, Leidy. 



Gregarina, Leidy. Pr. A. N. S., v, 208. Found in the larva of 

 Scarabeiis re/ietiis. 



E?nea, L,eidy. Pr. A. N. S.,v, 125. 



Characteribus refonnatis. Body linear, compressed. Head con- 

 tinuous with the body, with two lenticular depressions upon each 

 side. Mouth infero-terminal. CEsophagus styliferous. Eyes 4 to 6 

 anterior. Fresh water Nemertinea. 



I. Euiea Rubra, Leidy. Pr. A. N, S., v, 125. 



Body contracting irregularly, reddish or yellowish flesh colored. 

 Anteriorly and posteriorly obtusely rounded. Eyes two or three 

 black spots, placed in a line behind one another, upon each side of 

 the head ; often irregular. First pair of lateral depressions oppo- 

 site the interspace of the anterior two pairs of eyes ; second pair just 

 postero-lateral to the posterior pair of eyes. CEsophagus very long 

 and tortuous, villous, furnished at its bottom with a single spine or 

 nail-like tooth, and four others upon each side in a rudimentary con- 

 dition, enclosed in a sac. Intestine becoming obliterated posteriorly. 



