361 



srt cp/i 



each amphid; these ducts can be followed backward to near the pigmented 

 bodies soon to be mentioned, and possibly may be connected with them. The 

 external expressions of the amphids, each of which is symmetrical to two 

 lines, are of unequal diameter, without central markings, and are located 

 toward the front of the head; they are about as wide as the corresponding 

 portion of the head, each being about twice as wide as long. The two 

 greenish pigmented bodies mentioned above (org?, Fig. 2), are olive green in 

 color and present a nucleus in the midst 

 of a colorless spherical cell ( ?) as wide 

 as one of the cuticular annules in the 

 immediate vicinity. These bodies are 

 naturally rather difficult to observe 

 on account of the hairy nature of the 

 cuticle through which they are viewed ; 

 they are located well outside the in- 

 testine, one on each side of the body, 

 somewhat behind the base of the neck. 

 The broad cardiac constriction lies 

 opposite the eighth to tenth rows of 

 setae, and is about as wide as the 

 distance between these rows. The 

 thick-walled intestine presents a faint 

 lumen and is composed of cells of 

 such a size that about twelve occur 

 in each cross section. In the male, at 

 least, the intestine gradually becomes 

 one-half as wide as the body. There 

 is no pre-rectum. From the minute 

 anus, whose anterior lip is somewhat 

 elevated, the inconspicuous rectum 

 extends inward at right angles to the 

 ventral surface half way across the 

 body; the intestine itself extends past 

 the anus. No anal muscles are to be 

 seen. There are two kinds of colorless 

 granules of variable size to be seen in 

 the cells of the intestine; the largest 

 of these have a diameter equal to the 

 distance between the rows of somatic 

 setae; the finest of the granules are 

 exceedingly fine. The granules are not 

 so arranged as to give rise to a tessel- 

 lated effect. The more or less convex-conoid tail tapers from in front of the 

 anus to the tubular spinneret, which comprises two-sevenths of the whole 

 tail. This tubular spinneret is about as wide as one of the spicules of the 

 male; it is a simple truncate affair which tapers but very little. A marked 

 peculiarity of the posterior extremity of the nema is the existence of numerous 

 minute setae ; for a distance equal to the length of the spinneret the setae on 

 the portion of the tail immediately in front of the spinneret are very much 

 reduced and more numerous. The spherical caudal glands are located behind 

 the anus in the anterior fourth of the tail and empty through separate ducts; 

 each is about one-fifth as wide as the corresponding portion of the tail, or as 

 wide as one of the somatic annules opposite. Only two nuclei were seen in 



dint 



X100 



grnmajint 



Fig. 2. Internal anatomy of the head 

 end of Greeffiella dasyura. Lettering as in 

 Fig. 1. d int, one of the cells of the 

 intestine; crd col, cardiac collum; del amph, 

 duct connecting with the amphidial pore; 

 grn maj int, one of the larger intestinal 

 granules; grn min int, smaller intestinal 

 granules; int, intestine; lum int, lumen 

 of the intestine; nr, nerve ring; org ?, 

 organ of doubtful significance; set tb, 

 tubular seta. 



