440 cobb: new nematode genera 



single, distinct, guiding ring. Oesophagus widening considerably in front of 

 the middle to three-fourths as wide as the neck. First fascicle of nine supple- 

 mentary organs about twice as far in front of the anus as the proximal ends 

 of the spicula; second fascicle of about five, about twice as far from the anus as 

 the first; third fascicle of two still ftirther forward; the larger fascicles one-fourth 

 as long as the body is wide. Spicula faintly constricted in the middle, taper- 

 ing both ways; not cephalated; twice as long as the anal body diameter. 

 Flemming to glycerine. 



Habitat; distribution. Roots of plants and among algae, Potomac River and 

 its banks, Arlington Farm near Washington, D. C; Douglas Lake, Mich. Genus 

 represented in all parts of the woiid, and proposed for the reception of species 

 similar to the writer's Dorylaimus labyrinthostomus, in which the pharynx is more 

 or less immobile, radially striated and elaborately constructed. Dorylaimus 

 labyrinthostomus, Cobb, thus becomes Actinolaimus labyrinthostomus (Cobb). 



11. Antholaimus truncatus, n.g., n.sp. 



r-=. ..9 8- 2?.. .....'49^*. 99...... 1.5 mn. ^^P^ angular. Amphids unknown. 



1.5 3.5 4.1 3.8 2.6 Spear small, nearly as long as the 



lip region is wide. Pharynx cup-shaped, then fitting the spear. Oesophagus very 

 narrow, very suddenly enlarging a little in front of the middle to three-fourths 

 the width of the neck; lining unusually massive. Chain of contiguous circular 

 organs throughout the length of the body in the lateral fields, one-fourth to 

 one-third as wide as the body. Characters of Dorylaimus, but with the lips 

 petaloid and strongly developed, and specially modified and mobile. Flemming 

 to glycerine. 



Habitat; distribution. A single species from the roots of cotton plants, South 

 Carolina. 



12. Dorylaimellus virginianus, n.g., n.sp. 



Head set off by a narrow con- 



C:^c;-| 1^1 ^^ 3^^ ?|^ 1.5 n^. striction. Lips connate, rounded; 



one set of papillae near the mouth 



r_- .4 6.4 £4.3 -M- 96.5 1.4 mm. ■ u.-t^ xu xu 



l-=^.7 1.5 1.8 1.8 1.5 -^'^ """• openmg, the other on the margm 



of the head. Amphids three- 

 fourths as wide as the head. Spear Dorylaimoid, compound; first and 

 second sections of equal length, each a little shorter than the head is wide; 

 third section a little longer, expanded, faintly chitinized; followed by a short 

 constriction, and then a rudimentary, elongated, ellipsoidal oeosphageal bulb 

 one-third as wide as the corresponding portion of the neck. Posterior half of 

 the oesophagus three-fifths as wide as the neck. Supplementary organs in iso- 

 lated pairs located one in front of the other, one pair as far from the anus as is 

 the terminus, the other twice as far, all flattish-conoid. Spicula as long as the 

 anal body diameter; plump, strongly tapering, bent at the middle, cephalated by 

 expansion, without accessory pieces. Flemming to glycerine. 

 Habitat; distribution. A single species from Arlington. 



