FREE-LIVIXG XEMATODES 15 



testine is separated from the oesophagus by a cardiac collum one-sixth as wide 

 as the neck, and soon becomes two-thirds as wide as the body. The first few 

 cells of the intestine, at the cardiac region, are very small, with relatively large 

 nuclei that stain strongly. The intestine is separated from the rectum by a 

 pyloric collum one-fourth as wide as the corresponding portion of the body. 

 From the anus, whose posterior lip is elevated, the chitinized rectum leads in- 

 ward and forward a distance equal to the length of the anal body-diameter. The 

 granules of the intestinal cells are small and scarce. 



The tail tapers from the anus and ends in a slightly swollen terminus. A few 

 small, stiff, cylindroid, blunt caudal setae are to be seen, mostly about one-fourth 

 as long as the terminus is wide. The broadly saccate caudal glands, arranged in 

 a loose tandem in the anterior fourth of the tail, empty through distinct ducts 

 and elongated, narrow ampullae. What appears to.be an irregularly ellipsoidal 

 renette-cell is located at a distance behind the neck equal to the width of the body; 

 it is half as long as the body is wide, and three-fourths as wide as long. The 

 nerve-ring, which surrounds the oesophagus more or less obliquely, is accompa- 

 nied by distinct nerve-cells definitely grouped, both in front of it and behind, and 

 extending backward to near the cardiac bulb. From the small and inconspicuous, 

 but more or less elevated vulva, the conoid, non-chitinized vagina leads inward 

 at right angles to the ventral surface two-fifths the way across the body. The 

 eggs have a length nearly one and three-fourths times that of the body-diameter, 

 appear about half as wide as long, and have been seen in the uterus one at a time. 

 The medium sized, more or less tapering ovaries contain fifteen to twenty develop- 

 ing ova, for the most part flattened and arranged single file. 



The more or less slender, sub-acute, uniform, slightly yellowish spicula have 

 a simple and rather strong framework, and are one and one-fourth times as long 

 as the anal body-diameter. The proximal ends appear to lie opposite the body 

 axis. The triangular, blunt accessory pieces have a simple and rather frail frame- 

 work; the part applied to the spicula is one-fourth as long as they, while the ta- 

 pering apophyses lie a little backward and end opposite the body-axis. The ejac- 

 ulatory duct is one-fourth, and the testis one-half, as wide as the body. The 

 comparatively few (about a dozen) primary spermatocytes occur in the testis 

 in single file, then come three pairs double file these latter relatively huge. 

 That is to say, the primary soermatocytes increase much in size and then divide 

 transversely into very unequal parts, a small distal part and a large proximal 

 part, and these two unequal parts divide almost simultaneously in the longitudi- 

 nal direction. Thus there appear four cells arranged in two pairs side by side, a 

 small strongly staining pair with inconspicuous nuclei, and a large pair which 

 do not stain except in their relatively small nuclei which show about seven small 

 more or less globular chromosomes. These two divisions represent the usual 

 reduction divisions, and give rise to spermatozoa of very different size and ap- 

 pearance. The phenomenon is reminiscent of the formation of the polar bodies. 

 In some specimens the smaller cells, those that in their appearance remind one 

 of polar bodies, appear as if divided a second time, but there is uncertainty about 

 this. It is the writer's intention to prepare a separate report on this species 

 and its spermatogenesis. 



Habitat; remarks. Cape Royds; Bay, Cape Royds. Numerous specimens, 

 mostly somewhat shrunken. 



