FREE-LIVING FRESH-WATER NEMATODES 67 



corresponding radius of the neck, and opposite them the oesophagus is a 

 trifle narrower than it is either in front of or behind them. The oeso- 

 phagus, which at first is about half as wide as the base of the head, con- 

 tinues to have approximately the same diameter until after it passes through 

 the nerve-ring, which is somewhat in front of the middle of the neck. Be- 

 hind the nerve-ring the oesophagus becomes somewhat wider, and is finally 

 about two-thirds as wide as the base of the neck. The lining of the oeso- 

 phagus is a fairly distinct feature. The intestine, which becomes at once 

 nearly three-fourths as wide as the body, is set off from the oesophagus by 

 a distinct constriction. There does not appear to be any well developed car- 

 dia. The cells composing the intestine contain scattered granules, which 

 give rise to a very obscure tessellation, and also contain doubly refractive 

 granules, which, however are not spherical in form, though their diameter 

 in different directions is not very variable. The tail of the male tapers rap- 

 idly from the anus, so that at the end of the anterior fourth it has a 

 diameter but little greater than that of the terminal spinneret. Near the an- 

 terior end of the cylindrical part there occur a pair of subventral arcuate, 

 tapering setae, which are about as long as the corresponding diameter of 

 the tail. In front of these there is a ventrally submedian pair of papillae, 

 and also there is a dorsally submedian pair a little in front of these latter. 

 The spinneret is of a simple character, and has the terminus almost imper- 

 ceptibly swollen. There do not appear to be any setae on the spinneret. 

 A trifle in front of the proximal ends of the spicula there springs from a 

 ventrally submedian lines a somewhat weakly developed bursa, which extends 

 slightly beyond the body contour, but only does this in front of the anus. 

 It recedes into the cuticle at a point slightly in front of the caudal setae. 

 This bursa does not have any ribs and is not striated in any way. The two 

 equal, elongated, rather uniform, slightly cephalated spicula are a little 

 more than twice as long as the anal body diameter, and in their anterior 

 halves are nearly straight. In their posterior halves they are slightly 

 arcuate. At the point where they attain their greatest width they are about 

 one-fourth as wide as the corresponding portion of the body. Seen dorso- 

 ventrally they are somewhat narrower and straighter than when seen in 

 profile. The accessory piece appears to be compounded of a number of 

 small chitinous elements, the whole structure being a little less than one- 

 third as long as the spicula. It is not very strongly developed, and is not a 

 very conspicuous feature. The ejaculatory duct is about half as wide as the 

 corresponding portion of the body. There are two testes outstretched in 

 opposite directions. The blind end of the anterior testis is about as far be- 

 hind the base of the neck as this latter is behind the anterior extremity. 

 The posterior testis is smaller, but just how much smaller is unknown, as 

 its blind end could not be located in the single specimen examined. Little or 

 nothing is known concerning the lateral fields and the renette. 



Habitat: Fresh water pond, near Ocala, Fla. Bouin solution to 

 glycerine. 



