NO. 6 CLASSIFICATION OF NEMATODES — FILIPJEV 33 



Subfamily Hoplolaiminae. 



Genera: Paratylenchus Micoletzky, 1922; Atylenchiis Cobb, 1913; Procri- 

 conema Micoletzky, 1925; Hoplolahniis Daday, 1905; Criconema Hof- 

 manner and Menzel, 1914; Iota Cobb, 1913 (syn. Ogma Southern, 

 1914). 



KEY TO SUBFAMILIES OF TYLENCHIDAE 



1. (4) Mouth capsule prominent, wide or narrow, with or 



without teeth, always spearless. 



2. (3) No special knoblike appendages of the mouth cap- 



sule. The form of the mouth capsule variable. 



Diplogasterinae 



3. (2) The narrow mouth capsule has two knoblike hol- 



low appendages Tylopharynginae 



4. (i) Mouth capsule very narrow, spear-bearing, in some 



genera obsolete together with the spear. 



5. (8) Spear with or without basal knobs, not very large 



and strong; lost in some genera. 



6. (7) Free-living and plant parasitic. Body of typical 



nematodelike appearance in free-living forms, 

 swollen in the females of some plant-parasitic 

 species, but without large swollen cells inside. 



Tylenchinae 



7. (6) Insect parasites. Body of typical appearance in 



young stages, swollen in mature parasitic fe- 

 males, in some genera losing the nematodelike 

 body form; with swollen cells inside Sphaerulariinae 



8. (5) Spear strong and huge, always cephalated. Cuticle 



with peculiar annulation Hoplolaiminae 



The prominent feature of this family is the structure of the esoph- 

 agus, muscular in the anterior part with a well-differentiated middle 

 bulbus, and glandular in the posterior part. In most of the members 

 of the Tylenchinae, as well as in the Diplogasterinae, the posterior 

 portion of the esophagus is joined together and the boundary be- 

 tween it and the intestine is easily seen. In other Tylenchinae, e.g., 

 Aphelenchus, the esophagus is subject to further evolution, the 

 esophageal glands come out of direct connection with the body of 

 the esophagus, the tubular portion becomes narrow, and its connec- 

 tion with the intestine cannot be easily observed; sometimes that 

 part of the esophageal tube becomes short and the beginning of the 

 intestine is quite near to the nerve-ring. In another direction there 

 is a reduction of the anterior muscular part of the esophagus. 

 Throughout there is a reduction in the functions of the esophagus. 

 In most of the species of genera which contain plant-parasitic species, 

 the only remaining muscular part is the middle bulb. A further re- 



