SUB GENUS IOTONCHUS 



(S. S. 477) 175 



reaches two-fifths the way. back to the vulva. The ova are for the most part 

 arranged single file. 



This nemativorous species will probably prove cosmopolitan. About roots of 

 banana, Fiji; of Platonia insignis, Rio Janeiro, Brazil; roots of various plants, 

 Arlington Farm, Virginia, U. S. A. Fig. 60 (on the previous page). 



49. M. consimilis, n. sp. Amphids, unlike those of gymnolaimus, apparently 

 duplex, located a little behind the base of the lips ; one-fourth as wide as the cor- 

 responding portion of the head. Wall of the pharynx strongly developed. 



Rather closely resem- 3.2 9.1 26. 68' 86. 

 bles M. gymnolaimus, 2.4 2.7 2.7 2.4 2.1 1-1 M 

 but has the walls of the pharynx much more strongly cer- 

 atinized, and is of much smaller size. The pharynx is j~ela- 

 tively SO per cent longer. The spinneret is not swollen as 

 in gymnolaimus. Description and figures derived from a 

 single, immature female specimen from about the roots of 

 Platonia insignis Mart., Brazil. The figure of gymnolaimus 

 shows, on the ventral side, near the front of the pharynx, an 

 inward projection, probably representing the optical section 

 of the junction of elements in the pharyngeal wall. No 

 such appearance was observed in consimilis. Fig. 61. 



50. M. rapax, n. sp. Intestine about 12 to 20 cells in girth, faintly tessellated. 

 The female organs 'are probably double and symmetrical. The conoid tail tapers 



somewhat in front of the anus to a 

 plain, symmetrical, unarmed spin- 



2.5 6.5 21. 61. 90. , 

 27 272 276 271 fTT^* dl 



neret about one-sixth as wide as its 

 base. One and one-half tail-lengths 

 in front of the anus there is a con- 

 striction in the intestine, which ap- 

 pears to be due to the presence in 

 that region of ' commissures, as if, 

 possibly, nerves encircled the intes- 

 tine at that part. 



Found about the roots of plants, 

 Arlington Farm, Virginia, U. S. A. 

 Nemativorous. Only young females 

 have been seen. As its name, rapax, 

 indicates, this species is a rapacious 

 one, swallowing other nemas whole, 

 even when half as long as itself. 

 Fig. 62. 



51. M. rex Cobb. This "king" of the mononchs has low, broad, inconspicuous 

 labial papillae that do not interfere materially with the rounded contour of the 

 front of the head. The lips are bulky and powerful. No amphids have been seen. 

 The pharynx is armed with very powerful 2. 6. 20. 'se* 37 ei. 

 muscles. The intestine is tessellated. The fTe UT 2~. ?72 



lateral fields are one-fifth as wide as the 2 5>5 20> M 50 

 body. The conoid tail tapers more rapidly us F79 271 iTa t.5 ' - a - y - mB 

 at first, being nearly cylindroid in the posterior two-thirds, where it is about one- 

 eighth as wide as at the anus. The spinneret, which is slightly expanded, bears two 

 ventrally submedian papillae, after the manner of longicaudatus , but slightly larger 



1.4 



86. 



