46 NORTH AMERICAN 



width there is no spinneret. The lateral fields are about one-third as wide 

 as the body. The nerve-ring surrounds the oesophagus somewhat squarely. 

 On the dorsal side, a little behind the cardiac constriction there is a body 

 which presses the intestine a little to one side, which may perhaps be the 

 renette cell. This body has a length as great as the corresponding body di- 

 ameter, and is about one-fourth to one-third as wide as long. The vulva is 

 somewhat elevated, and from it the vagina extends inward at right angles to 

 the ventral surface about one-third the distance across the body. There are 

 two symmetrically disposed, reflexed ovaries, the blind ends of which lie 

 near the vulva, the position depending to a considerable extent upon the de- 

 velopment of the much elongated eggs. The ovaries are moved backward 

 and forward to a certain extent in accordance with the stage of develop- 

 ment of the eggs. The eggs, which have been seen in the uteri one at a time, 

 are much elongated four or five times as long as the body is wide 

 and about one-fifth as wide as long. They appear to be deposited before 

 segmentation begins. 



Habitat: Roadside pool, Douglas Lake, Michigan. Sublimate to 

 balsam. 



SPILOPHORA, Bastian, 1865. 



Fig. 5, Plate III. 

 5. Spilophora canadensis, n.sp. 



The thin, transparent layers of the colorless, practically naked cuticle 

 are traversed by 750 transverse striae, resolvable with high powers into 

 rows of dots, which at the lateral wings are so modified as to give rise to 

 two distinct longitudinal rows of dots of larger size. Along the middle of 

 the body one of these rows is more pronounced than the other. Opposite 

 the base of the neck the distance between these two longitudinal rows is 

 about four times as great as the distance between two of the dot-like ele- 

 ments. There are no eye-spots, nor have any distinct traces of amphids been 

 seen. If the latter are present they must be very inconspicuous. The lips are 

 so small that it is very difficult to count them, but there appear to be twelve, 

 each one obscurely conical. There are no very marked subdivisions between 

 these lips, so that the shallow cyathiform anterior portion of the pharynx, 

 (a, Fig. 5) which is about half as wide as the head and about one-third to 

 one-half as deep as wide, is not prominently striated radially as is some- 

 times the case in this and related genera. From the slightly depressed vulva, 

 the vagina leads inward at right angles to the ventral surface about half way 

 across the body, where it joins the two symmetrically-placed uteri. The re- 

 flexed ovaries reach fully half way back to the vulva, at least in young speci- 

 mens such as have been examined, and contain a dozen to twenty developing 

 ova arranged in more or less double file. The eggs appear to be elongated, 

 somewhat longer than the body is wide and about one-third as wide as long. 

 It is possible, however, that there is some error here as the description is 



