FREE-LIVING FRESH-WATER NEMATODES /I 



walled is separated from the oesophagus by a distinct and deep constriction, 

 and becomes at once about three-fourths as wide as the body. The anterior 

 portion of the intestine is characterized by the presence of a considerable cav- 

 ity, which, however, soon narrows, and, as the internal wall of the intestine 

 is rather strongly refractive, the narrow, sinuous lumen is a very conspicuous 

 feature. From the rather conspicuous depressed anus the rectum, which is 

 rather strongly chitinized and somewhat longer than the anal body diameter, 

 extends inward and forward. The tail is somewhat concave conoid from 

 the anus to the very acute terminus. There are no caudal glands. The lat- 

 eral fields appear to be about one-third as wide as the body. The nerve- 

 ring surrounds the oesophagus somewhat squarely. The excretory pore 

 appears to be located near the nerve-ring. The nature of the internal sexual 

 organs remains uncertain, but the vulva is evidently located near the middle 

 of the body. The description is derived from an immature specimen. 



Habitat: Cranberry bog, Arlington Farm, Virginia. Flemming so- 

 lution to glycerine. 



BASTIANA, de Man, 1876. 

 Fig. 23, Plate VIII. 



.2 8. 18. 58. 89. 

 21. Bastiana exihs, n.sp. - 1.4 mm. 



5 -8 i. i. 5 i.i 



The moderately thick layers of the transparent, colorless, naked cuticle 

 are traversed by about eight hundred forty transverse striae, which do not 

 appear to be further resolvable. These striae exist in the outer as well as 

 inner cuticle, so that the entire contour of the body is crenate. Rather con- 

 spicuous lateral wings are present, the optical expression of which is two 

 distinctly refractive longitudinal lines opposite the lateral fields, separated 

 from each other by a distance somewhat greater than the width of one of 

 the annules of the cuticle. The gradually tapering conoid neck ends in a 

 somewhat truncate head, which is not set off in any way, and which bears 

 a circlet of at least six cephalic setae, of which four submedian are the 

 longer, and somewhat longer than the head is wide. Possibly each of these 

 latter is accompanied by a shorter seta, thus making ten in all. Apparently 

 labial papillae are present, but they have not been sufficiently clearly seen 

 to permit of enumeration. There is no distinct pharynx. The amphids, lo- 

 cated as in B. gracilis deMan, are somewhat in the form of the end of a 

 shepherd's crook. They are perhaps to be regarded as broad spiral bands of 

 about one turn. So regarded, the band may be conceived to begin on the 

 ventral side where its end is rounded and its contour distinct, pass forward, 

 and then curve backward and end indefinitely at a point somewhat in the 

 rear of the beginning. The amphids are half to two-thirds as wide as the 

 corresponding portion of the neck, and somewhat longer than wide. There 

 are no eye-spots. The oesophagus begins as a tube fully two-thirds as wide 

 as the head. It gradually increases in diameter as it passes backward, and at 



