SUBGENUS PRIONCHULUS 



(S. S. 465) 163 



Zahnelung erstreckt sich iiber eine etwa 0.016 mm. lange Strecke und beginnt 

 distalwarts etwa in der Hohe der Spitze des dorsalen Zahns." The ellipsoidal 

 eggs occur in the uteri one at a time, are about as long as the body is wide, and 

 two-thirds as wide as long. 



Found among the roots of Alopecurus denticulatus , as well as aquatic habitats 

 in the bottom of ditches and lakes in Germany. Fig. 36 and 36a (after Brakenhoff)' 



23. M. muscorum (Dujardin) Bastian. The oldest, and one of the best known 

 species. Intestine tessellated. Tail conoid and arcuate. The reflexed ovaries, each 

 containing about a dozen ova arranged 

 more or less in single file, extend half way 



fpl 



mrpt 



2. 



24. 



;,32 



2.5-3. 



92. 



1.9 rain 



2.1 2.7 3.2 3.6 1.6 2. 3.2 3.7 4.4 2.5 



back to the projecting vulva. The eggs are one and one-half times as long as the 

 body is wide and three-fourths as wide as long. The anterior sexual organ is 

 somewhat the larger. Fig. 37, left. 



This is a beautiful and rather common cosmopolitan species, occurring in swamps, 

 marshes, meadows and moorlands. It has been found in various parts of Europe 

 and is not uncommon in the United States. It was first found by DujardinWn the 

 Jardin des Plantes, Paris, where it still thrives ; the writer recently found it about 

 the roots of some heather imported thence. It feeds on smaller animal organisms, 

 among them other nematodes. The following is a variety : 



M. muscorum (Dujardin) Bastian macrolaimus, n. var. Besides differing slightly 

 in proportions from the type form of the species, the variety has a somewhat larger 

 pharynx, with smaller denticles on the ventral rib. The submedian papillae of the 

 outer sets are apparently double instead of triple, though at 

 some distance behind the outer submedian papillae there is a 

 special submedian innervation. Most of these minor differences 

 are set forth in figures 36 and 37. 



Found in Cladonia rangiferina, tamarack swamp, Wisconsin, m 

 U. S. A. Fig. 38, right. 



24. M. longicollis, n. sp. A species resembling M. mus- 

 corum, but which differs in the proportions of the various parts *"- 

 and in the conformation of 



m ikl 



3.1 



10. 27. 



93. 



the pharynx, the denticles 2.2 2.4 2.3 2.1 1.8 i> "" 

 of which are irregular and inward pointing. Submedian papil- 

 lae of the outer row double, instead of triple as in muscorum. Amphids relatively 



