432 Dr. Johnston on Entozoa. 



watery-white, veined with milk-white and clear lines, the 

 veining less distinct on the dorsal than on the ventral aspect. 

 The body is narrowest anteriorly, and in front there is a small 

 piece which the animal can elongate to a slight extent and 

 make more or less concave ; the sides of this piece, from their 

 greater opacity, appear to be thickened, but they are not con- 

 formed into proper suckers. A little behind this frontlet, and 

 on the ventral surface, is the mouth, which has the appear- 

 ance of a very short, thick proboscis of a slightly corneous 

 texture, striated and obscurely three-lobed on the outer edge : 

 it can probably be protruded more or less, and when fully 

 extended by pressure resembles a short inverted cone (fig. 3. 

 a.) A little posterior to the proboscis we find generally, for 

 they are not constant, two ill-defined spots or organs (b) ; and 

 posterior to them, in the mesial line, a round viscus filled with 

 granular matter (c), above which there is usually to be seen a 

 yellowish-brown capsule or vesicle (o) with a long tortuous 

 thread attached to it, which runs forward obliquely by the 

 side of the mouth, opening outwardly on the margin below 

 the frontlet (d). Proceeding backwards in our examination 

 we next observe two very conspicuous round spots (e, e) se- 

 parate although closely approximated, and placed one on each 

 side of the axis of the body : they are filled with granules, and 

 form a marked character in the worm from their distinctness, 

 and from being encircled with milk-white vessels, from whose 

 posterior arch numerous capillary branchlets go off to ramify 

 in the space between them and the sucker. The posterior 

 edge of the body is truncate with a slight prominence in the 

 middle, whence the sucker originates, and above which the 

 anus opens. The sucker is very large, subpedicellate, circular, 

 concave, rough with tubercles arranged in rows, and covering 

 rather more than two thirds of the disks, for the upper side is 

 smooth ; and it is also furnished with two pairs of elongate 

 spiriform teeth so placed as to form by their union a sort of 

 oblong or horse-shoe shaped space running from the inferior 

 margin to the centre of the sucker (s) . 



Along each side of the body, running from near the head 

 to the tail, we readily distinguish, by its transparency, a large 

 vessel that seems as if it were rather excavated in the granu- 



