cobb: new nematode genera 441 



13. Nygolaimus pachydermatus, n.g., n.sp. 



7.7 22. 56 98. 



1.9 2.4 ■ 2.5 1.9 



f-=^r- -6 v-7 22. 56 ^?*„-- 1.8 nrni. Measurements derived from a 



t— t^l.l 1.9 2.4 2.5 1.9 . r^ +• 1 X, - 1 



young specimen. Cuticle thicker 



on the tail. Lips connate, set off by constriction. Amphids half as wide as the 

 corresponding part of the head. Spear half as long as the head is wide, conical, 

 slender, pointed, tooth-like; without guiding-ring. Posterior half of the oesoph- 

 agus enlarged to three-fourths the width of the neck. Flemming to glycerine. 

 Habitat; distribution. A single species from roots of cherry trees, Tokyo, 

 Japan. Other species occur in Eastern United States. 



14. Trichodorus obtusus, n.g., n.sp. 



Papillae fiattish-conoid, outward 

 r^.^'LiA Li^J IL; 22.^ — IMl — ii^^- i. mm. pointing, on margin of head. 



^— '^l.g (3.3) 3,6 4.1 4.V 2.3 \ f ° . 



Amphids nearly halt as wide as 



a^^ l'.l (lis) ^sU ^3:9 ~4.4 ^2.1 ^-^ """• the head. Pharynx exceedingly 



narrow. Spear flexible, exceed- 

 ingly slender, inclosed in a long muscular sheath. Oesophagus mainly 

 narrow and tubular, about one-sixth as wide as the neck. Supplementary organs 

 three, fiattish-conoid, distinctly interrupting the ventral contour; the hindermost 

 opposite the proximal ends of the spicula; the second twice ais far from the anus 

 as the first ; third nearly twice as far from the anus as the second. Spicula slender, 

 uniform; proximal ends cephalated by expansion. Flemming to glycerine. The 

 measurements in parentheses are taken at the base of the spear. 



Habitat ; distribution. Several species from various parts of the United States, 

 the present one from about the roots of grasses, Arlington. 



15. Achromadora n.g. minima (Cobb) 



r*.o2-8 "^^ ■ 17. . .'45' 87. sinin,. Habitat; distribution. Genus pro- 

 L''^2.5 ? • 3^ 4.4 2.8 J t \-u 4.- f+i, •; ' 



posed for the reception ot the writer s 



Chromadore minima, and similar soil and fresh-water species. Distinguished 

 from Chromadora by the presence of well developed spiral amphids. The dor- 

 sal tooth is farther back and is opposed by a small ventral "pocket" as shown in 

 the figure of Chromadora minima. Measured fresh. Species found, probably, in 

 all parts of the world. Species are known to the writer from Australia, Fiji, and 

 various parts of the United States. 



16. Cryptonchus nudus, n.g., n.sp. 



<_ 3.2 9.2^ 26. . '54^*. .91. > 1.9 mm. Striae resolvable with difficulty, and 

 '-""'^1.4 i.v ■ 2. 2.2 1.5 ^jj^Q rows of dots. Lips six, rather 



inconspicuous, each with one papilla. Amphids as wide as pharynx, about one- 

 fourth as wide as the corresponding portion of the neck; located opposite the 

 junction of the first and second quarters of the pharynx. Oesophagus plain, 

 half as wide as neck, lining relatively massive. Eggs elongated. Hot sublimate 

 to balsam and Flemming to glycerine. Caudal gland apparently a single cell. 



Habitat; distribution. Single species. Differs from Cylindrolaimus in the 

 form of the amphids, and the strongly developed oesophagus with its various 

 regions, and in the presence of a dorsal tooth at the base of the pharynx and in 

 the absence of setae. Found about the roots of aquatic plants, Potomac River, 

 Arlington and in Douglas Lake, Mich. 



