RESEARCHES IN HELMINTHOLOGV AND PARASITOLOGY. 1 53 



is much infested with parasites. From half a dozen to several dozen 

 Flukes are found in the liver, and a ciliated infusorian in the 

 branchial cavity. 



The Fluke is a minute larval Distomum, with the following char- 

 acters : Oval, obovate, clavate, or nine-pin like ; head rounded, with 

 a conspicuous nipple-like papilla on each side (which, when seen 

 in the lateral view of the animal, gives the appearance of a beak to 

 the head) ; tail obtuse, with a minute terminal pore. Integument 

 finely granulate, the granules arranged in alternating transverse 

 series. Oral acetabulum twice the size of the ventral, which is cen- 

 tral or nearly so. Mouth large, unarmed. Pharynx minute, with 

 a short, narrow gullet, ending in two pouch-like stomachs, which 

 extend to the ventral acetabulum. A distinct body cavity, with no 

 other contained organs than those just mentioned. A small orifice 

 occupies the median line nearly midway between the acetabula; but 

 no appearance of generativ-e apparatus. Length of animal in the 

 contracted state .24 mm. ; width .15 mm. ; length in the elongated 

 state to .36 and .42 mm. ; width. 09 mm. Oral acetabulum .072 mm.; 

 ventral acetabulum .042 mm. The species may be named Distonnim 

 cornifrous. 



It is probable that this little Fluke undergoes its further develop- 

 ment in some of the shore birds or fishes which use the Douax fosser 

 as food. 



The infusorian infesting the Digger is a 'rrichodina, resembling 

 that which is found on the Hydra or fresh-water polyp, and which 

 is also stated by Stein to live on the gills of the pike and the fins of 

 the stickleback. The Trichodina is bell-shaped, with a wreath of 

 cils near the top and a circle of cils at the margin beneath. It is 

 .048 mm. broad and from .035 to .036 mm. high. Though living 

 on rt marine mollusk, it too nearly resembles the Tric/iodina pediculus 

 of fresh- water animals for him to think of giving it another name. 



[January, 1879. Nos. 467, 468. See Bibliography.] 



On Gordius and on some Parasites of the Rat. — Prof. Leidy exhib- 

 ited a curious knotted mass of living hair-worms, Gordins rohnstus ? 

 which had been sent to him by Dr. S. T. Roman, of Conowingo, 

 Cecil county, Md. The mass had been picked up in a gutter at the 

 edge of a forest near Conowingo, on a rainy morning of December 

 15, 1878. It contained 52 male individuals and 7 females. The 

 former ranged from 8 to 25 centimeters in length by yi to 2-3ds of 

 a millimeter in thickness; the latter range from 14 to 19'^ centi- 

 meters in length by i millimeter in thickness. The females are 



