442 cobb: new nematode genera 



17. Nannonchus granulatus, n.g., n.sp. 



Head continuous. Lips six, thin, 

 ?,^ol.4 9.3 17. '52'*^'' .91. ,i.imra. arched over pharynx, each with one 



f^^l.e ""3. 3.4 4.3 2.5 .,, o . , ,■, . . 



papilla. Spiral amphids of two 

 winds, one-fourth as wide as the 

 head. Oesophagus two-thirds as wide 

 as the head; finally expanding to two-fifths as wide as the base of the neck; lining 

 very distinct. Eggs ellipsoidal, as long as the body is wide. No supplementary 

 male organs or papillae; about seven finger-shaped ventrally submedian setae on 

 the anterior two-thirds of the tail. Spicula tapering, nearly straight, somewhat 

 longer than the anal body diameter, accompanied by a relatively massive acces- 

 sory piece, parallel to and two-thirds as long as themselves. Distal end of ac- 

 cessory piece expanded laterally, and relatively massive. Flemming to glycerine. 

 Habitat; distribution. A single species found about roots of aquatic plants, 

 Potomac River, Arlington. Another similar species, Long Key, Fla. 



18. Oionchus obtusus, n.g., n.sp. 



/-^ 2.5 7.6/? .23, '57^^ 98- . , .9 mm. ^eck conoid, convex-conoid at the 

 t^^^2.5 3.6 4.6 4.2 2.9 head. Lips confluent; region low, flat. 



Amphids at the slight labial constriction; one-fourth as wide as the lip region. 

 Pharynx narrow; cylindroid or prismoid. Somewhat arcuate dorsal tooth, like 

 a short Dorylaimoid spear, but not hollow. Oesophagus beginning two-fifths as 

 wide as the head, almost imperceptibly expanding to the middle; thence cylindrical, 

 and one-half as wide as the neck; three small organs at base, as in Trilobus. 

 Lining very distinct. Peculiar series of four small internal lateral organs just be- 

 hind the neck. Terminus of tail with peculiar large pore, presumably a peculiar 

 spinneret pore. Eggs elongated. Flemming to glycerine. 



Habitat; distribution. About the roots of grass, borders of irrigation ditch, 

 Jamaica, West Indies. 



19. Udonchus tenuicaudatus, n.g., n.sp. 



- . ,- ,,25 Traces of labial papillae. Amphids 



0, „ 1-9 8.4 „ 16. 01 °°: > .5 mm. ^ ^ 



— °2.3 3.2 3.ii 3.6 2.6 transverse, ellipsoidal, one-fifth as 



ong as the corresponding diameter of the neck. Pharynx cyathiform, then 

 narrow, with small, acute, narrow, forward-pointing dorsal tooth at the base 

 of cyathiform portion, opposed by a very minute ventral tooth. Anterior two- 

 fifths of the oesophagus three-fifths as wide as head, then suddenly slightly 

 increasing in diameter, so that at the nerve-ring it is half as wide as the neck; 

 enlarging finally into a spherical bulb with simple valve. Thin-shelled eggs, 

 elongated, one at a time in the uterus. Flemming to glycerine. 



Habitat; distribution. On aquatic plants and among algae. Cockpit Springs, 

 Jamaica, West Indies. 



20. Diploscapter n.g. coronata (Cobb) 



Habitat; distribution. Com- 

 C_ 4.5... i6,5/_. 24.2 .'55' .89.5 .4 mm. mon about the roots of diseased 



V 4 . 5^4 6.1 6 . o c . o 



50 plants, especially in warm coun- 



C= i:!" • -iii =■ -Ls '7.1 '5:2 -2^ - '^5 '"'"• tries. Genus established to re- 

 ceive the writer's Rhabdilis 



