JUNE 19, 1932 COBB: METONCHOLAIMUS PRISTIURUS 447 



The osmosium, 87, of the enteric efferent is located about one-third the 

 distance from the anus to the vulva, and may usually be seen on the dorsal 

 side of the intestine, being mainly visible on account of the somewhat 

 greater transparency of its tissues. The narrow uterine efferent duct, ut. 

 eff., 79, 85, is very difficult to follow throughout its length, and usually can be 

 seen only in specially favorable specimens. Its connection with the posterior 

 end of the uterus is sometimes easy to see, near 30. Its connection with the 

 uvette is also nearly always easy to see, and it may be followed thence for- 

 ward a short distance, but to trace it far is usually a matter of some difficulty. 



The thirty-two flask-shaped elements of the uvette have their necks con- 

 centrated at the pore. The wall of the uterine duct, as previously described, 

 spreads out over the uvette, and beneath it the thirty-two elements form a 

 craterlike affair leading to the uvette pore. This pore opens into the some- 

 what duplex (but really monoluminal) corridor of the caudad part of the 

 intestinal efferent. This latter efferent may show signs of forking at a dis- 

 tance in front of the uvette about equal to the corresponding body diameter, 

 but is seldom, if ever, really bifurcate until behind the uvette. 



Or, following the demanian system from the rear toward the uvette: Where 

 the moniliform glands approach the uvette, they join to form a two-fold 

 structure, and the pore of the uvette is placed between the two parts of this 

 double structure. The structure of the tunic of the demanian system opposite 

 the uvette presents two sets of exceedingly fine symmetrically arranged 

 elements, one sloping 45 right, the other left, which continue forward. 

 This "spiral" structure can be seen throughout the duplex portion of the 

 demanian system now being described, namely that portion in the vicinity 

 of the uvette. 



Sperms, 61, are to be seen at the cephalad end of the uterus i.e., the sper- 

 matheca, where the oviduct joins the uterus, sometimes in a mass comprising 

 scores of sperms, each about one-tenth as wide as the corresponding portion 

 of the body. They are rather difficult to see except when they are present 

 in considerable numbers. 



MALE. Fig. 3. 



0.8 53 11. SM_ &e. ^, 



The spicula and other male organs, b.a "/" "ii ii " ' " iVs' ^ -^oi 



The tail of the male is more or less like that of the female in form, but is 

 somewhat larger, more arcuate, and far more flexible, even prehensile, as Fig. 

 2 indicates. It diminishes a little more suddenly in size at the anus, and is 

 armed with special setae and papillae. The two, equal, colorless, long and 

 very slender, uniform spicula, 57, 58, seven times as long as the anal body 

 diameter, are almost imperceptibly cephalated by expansion. They are 

 simple and frail looking, their proximal ends lying more or less opposite the 

 body axis. A long slender, duplex, nucleated retractor muscle, 16, extends 

 forward from the proximal end of each spiculum to the body-wall in the cor- 

 responding subdorsal region, near 12; an antagonistic protrusor muscle, of 

 about equal size ensheaths each spiculum. The small inconspicuous guber- 

 naculum, 42, lying near the anus, is double and straight. Its two equal parts 

 are somewhat frail and simple, but are expanded internally so as to be visible. 

 They are only about half as long as the anal body diameter, and lie against 

 the tips of the spicula in such a way that their swollen and more visible 

 proximal ends, 42, lie nearly opposite the axis of the base of the tail. 



There is a single inconspicuous preanal ventral papilla, 22, very close to the 

 anus, 21, but readily seen when searched for. There are about ten small 



