NO. 6 CLASSIFICATION OF NEMATODES FILIPJEV 2/ 



Villot, 1876, preocc. ; syn. Dipeltis Cobb, 1891, preocc.) ; Didelta Cobb, 

 1920; Acmaeolaimns Filipjev, 1918; Sphaerocephalum Filipjev, 1918; 

 Aponchium Cobb, 1920 ; fCampylaimus Cobb, 1920 ; fPseudolella Cobb, 

 1920. 

 Subfamily Sabatieriinae. 



Genera: Sabatieria Rouville, 1903 (syn. Parasahatieria de Man, 1907); 

 Kreisia Allgen, 1929; Alaimonema Cobb, 1920; Pepsonema Cobb, 

 1920 ; Mesonchium Cobb, 1920; Dorylaimopsis Ditlevsen, 1919 (syn. 

 Xinema Cobb, 1920) ; Filipjeva Ditlevsen, 1926. 



KEY TO SUBFAMILIES OF LINHOMOEIDAE 



1. (2,3) Amphids roundish, i.e., spiral in one winding. . . Linhomoeinae 



2. (1,3) Amphids horseshoe-shaped, oval, or roundish in 



general shape, sometimes on a specially differen- 

 tiated cuticular plate; in several genera both 

 ends of the horseshoe come so near together as 

 to touch each other (the amphid can then easily 

 be mistaken for a spiral one) Axonolaiminae 



3. (1,2) Amphids spiral in several windings Sabatieriinae 



This family is different in many respects from the Monhysteri- 

 dae. The cuticle is never so coarsely striated as in many members 

 of the Monhysteridae ; it is alvi^ays very soft and pliable, mostly with 

 a very fine striation or plain. The head is rounded and the mouth is 

 formed as in the Monhysteridae, but the chitinous ring conspicuous 

 in monhysterids is less prominent or sometimes quite obliterated (fig. 

 55). The most characteristic features are the spicules, strongly 

 curved and accompanied by a double backward-pointing gubernacu- 

 lum (fig. 56). In some genera the spicules are double but with the 

 same gubernaculum (figs. 57, 58). The division of the group into 

 subfamilies is based chiefly on the form of the amphids. In the 

 Linhomoeinae the amphid is roundish, and an oblique incision of its 

 border reveals its true nature as a spiral of a little more than one 

 turn. The manner of their origin seems also to be different from 

 that in the Monhysteridae. In the Axonolaiminae the amphids have 

 the form of a bent horseshoe, an elongated oval, as a rule, or are 

 roundish (fig. 59) ; it is probable that this form is to be considered as 

 more primitive even than the spiral one. In Diplopeltis this horse- 

 shoe is supported by a special chitinous plate (fig. 60). In the Saba- 

 tieriinae the amphid is a regular spiral in several turns, very similar 

 to that of the Comesominae, but the spicules afford a very good dis- 

 tinguishing character for the two groups. 



Herewith we come to the end of the typical free Nematoda. 



There are to be noted among them some transitions to the para- 

 sitic life. The impulse was certainly given by the peculiar semipara- 



