FREE-LIVING NEMATODES 19 



possibly it is just behind the nerve-ring. The small, weak, tubular, non-chitinized 

 vagina leads into a uterus which is five times as long as the body is wide. The 

 eggs are about four times as long as the body is wide, and one-fifth as wide as 

 long. The medium sized cylindroid ovary contains about twenty-five ova, 

 arranged somewhat irregularly. The tail of the male is like that of his mate 

 except that it is conoid nearly to the terminus. The very slender uniform spicula 

 are two and one-half times as long as the anal body diameter. Their frame- 

 work is simple, and the proximal ends lie somewhat dorsal to the body axis. The 

 single accessory piece is frail, its framework simple; the applied part being one 

 eighth as long as the spicula, the blunt, backward pointing apophysis being one- 

 fifth as long as the anal body diameter and having its proximal end opposite the 

 body axis. The ejaculatory duct is one-third, the testis two thirds, as wide as the 

 body. 



Habitat; remarks. Cape Royds. Six females and three males, in fairly good 

 condition. 



9. Monhystera f rigida, n. sp. About 1400 striae give to the margin a crenate con- 

 tour. The very inconspicuous lips are probably three in number. The amphids 

 appear circular, but are really reg- < ^ , 36 



ular spirals of one and one-half lb "~"/|P " 3 9 ' 7 18>1 ' B? 

 winds, having a raised transverse 

 ridge extending part way across. 

 A deeply staining nucleus, of the 

 same size and character as the 

 nuclei of the nerve cells near the ring, occurs immediately in front of each amphid. 

 In the posterior end of the oesophagus there are two, possibly three, elongated, 

 granular gland-cells, quite as long as the body is wide. The rectum is prominent. 

 The vagina is small and weak. The eggs are about four times as long as the body 

 is wide. The rather narrow, cylindroid ovary contains twenty or more ova, arrang- 

 ed mostly in single file. The uniform slender, frail, sub-acute spicula are one and 

 one-half times as long as the anal body diameter and lie with their proximae op- 

 posite the body axis. The very inconspicuous, very slender and frail acces- 

 sory piece is bent so that the applied part is one-third to one-fourth as long as the 

 spicula, while the uniform backward bending part is one-fifth as long as the anal 

 body diameter. Its proximal end lies to the ventral side of the body axis. The 

 ejaculatory duct is one-third, the testis two-thirds, as wide as the body. 



Habitat ; remarks. Cape Royds. The single female and the two males examined 

 were in fair condition. 



10. Monhystera polaris, n. sp. The 600 striae give to the margin a minutely 

 crenate contour, most plainly to be seen just behind the anus. The three double, 



more or less distinct lips 

 ^ j 4i are fairly developed. Two 



'-> i BO innervated papillae occur 



! K5 2 ' 5 2 ' 6 3 ' 4 2>1 on each of the lips, six 



I i. 11. 21. -M- 84. papillae in all. The am- 



an w/?^-V'/,/ i.V^2.~5 2.V~ 2.V~ 2.7 Illma1 ' phids are sunken, but 



usually show a well stain- 

 ed projecting margin two- 

 thirds as wide as the amphid. A little in front of each amphid is a single some- 

 what spherical nucleus, one-fourth as wide as the oesophagus, containing granules, 



