cobb: new nematode genera 439 



as wide. Bulb of spear two-fifths as wide as the corresponding portion of the 

 neck. Median bulb ellipsoidal, two-thirds as wide as the neck. No supplemen- 

 tary organs or special male papillae. Spicula about three times as long as the 

 anal body diameter extending nearly straight forward, but slightly arcuate, 

 and tapering in the distal third to the blunt, somewhat cephalated tips; proximal 

 two-thirds uniform, one-fourth as wide as the corresponding portion of the 

 body. Flemming to glycerine. 



Habitat; distribution. A single species from Arlington. 



8. Isonchus radicicolus, n.g., n.sp. 



Wing single. Spear simple, mi- 

 C^ lis |l|^"^2:8 "a! ^f:f ■ 1-1 """• nute, with double guide, some- 



what wider than one of the 



f_ 2.2 10,3/_ 11.8 -M 96.5. .8mm. ,. , , tj . x 



*-"^ 1.9 3^ z.i 3.8 2.5 adjacent annules. rrolate me- 



dian bulb, two-thirds as wide as 

 the neck. Posterior swelling fully half as wide as neck, ending indefi- 

 nitely. No male supplementary organs or papillae. Spicula tapering, one 

 and one-half times as long as the anal body diameter; proximal ends cephalated 

 by constriction. Accessory piece parallel, half as long. Bursa extending from 

 opposite the proximal ends of the spicula to terminus; one rib barely in front 

 of the anus; four others together toward the terminus, all smaller, especially the 

 final. Female tail with two terminal innervations. Bursa with ribs more numer- 

 ous and more strongly developed than in Tylenchus. Flemming to glycerine. 



Habitat; distribution. Single species from soil about the roots of cotton 

 plants, Springfield, South Carolina. 



9. Discolaimus texanus, n.g., n.sp. 



r^ .5 8.2 24.1 .'41^° 97.9 1.3 mm. ^^P^ connate, palmately innervated, 

 ^ '' 1.4 2.6 3. 3.2 1.9 margin crenate. Papillae several to 



each lip. Amphids half as wide as the corresponding part of the head, appar- 

 ently connnected with lateral series of spaced ellipsoidal internal structures 

 extending from end to end of the body. Spear tapering, rather stout, about 

 as long as the lip region is wide, with single guiding-ring. Posterior three-fifths 

 of the oesophagus, two-thirds as wide as the neck; lining very distinct. All the 

 characters of Dorylaimus, but with the lip-region strongly modified to form a 

 mobile sucking disk for use in opposition to the spear. Flemming to glycerine. 

 Habitat; distribution. The present species from the roots of alfalfa, San 

 Antonio, Texas, and from roots of citrus trees. Riverside, California. Wide- 

 spread genus, known to the writer from the West Indies, Texas, California, Japan 

 and Europe. 



10. Actinolaimus radiatus, n.g., n.sp. 



Amphids about one-third as wide 

 C:^c j| Ifl — '^{[r, '^e! ^rX' ^'^ '™' as the head. Pharynx as deep as 



head is wide, lined with six radia- 

 Vw- — '^i.s 3. 3.6 2. 1.4 tmg grooved, strong, chitmous ribs. 



Mouth opening circular, half as 

 wide as the head, very finely corrugated, leading to the cup-shaped pharynx. 

 Spear somewhat longer than the head is wide, one-fifth as wide as the head, with 



