NO. 6 CLASSIFICATION OF NEMATODES FILIPJEV yj 



Henry (1915), then followed by Skrjabin (1923), Yorke and Maple- 

 stone (1926), and others, seems to be much happier. 



The vertebrate parasites in general have been soundly placed in 

 the system of classification, but the same hardly could be said about 

 the parasites of arthropods monographed in recent years in Brazil 

 (Travassos, 1929; Artigas, 1930). In these papers the Brazilian 

 authors tried to build up a system quite independent from the exist- 

 ing system of parasites of vertebrates. But the parasites of inver- 

 tebrates cannot be considered as different from other Oxyurata as a 

 whole. The one-spiculed genera of oxyurids of arthropods are so 

 similar to the one-spiculed genera of oxyurids of vertebrates that 

 they can not be separated and must be referred to the same system- 

 atic group. Travassos (1930) himself in a later paper came to the 

 same general conclusions in trying to build a system embracing both 

 biological groups. Several hints from his work are used in the sketch 

 of the system below. 



In the review below there is given the systematic distribution of 

 oxyuroid genera parasitic in invertebrates only. For the parasites 

 of vertebrates Yorke and Maplestone (1926) and Baylis and Daub- 

 ney (1926) should be consulted. 



KEY TO FAMILIES OF OXYURATA PARASITIC IN INVERTEBRATES 



1. (6) Spicules two (obsolete in some Kathlaniidae). 



2. (3) Male without a preanal sucker Atractidae 



3. (2) Male with preanal sucker or pseudosucker devel- 



oped as a differentiation of precloacal muscula- 

 ture. 



4. (5) Polymyarian. Lips poorly developed Heterakidae 



5. (4) Meromyarian. Lips strongly developed, well sepa- 



rated Kathlaniidae 



6. (i) Spicule single Oxyuridae 



Subfamilies and Genera of the Family Atractidae 

 Subfamily Cosmocercinae (including Oxysomatiinae). 

 Subfamily Atractinae. 

 Subfamily Carnoyinae, subfam. nov. 



Genera: Rondonema Artigas, 1926; Canioya Gilson, 1898; Pararhabditis 

 Baylis and Daubney, 1926 (= Pseud or habditis Sziits, 1912). 

 Subfamily Rhigoneminae Artigas. 



Genera: Dudekemia Artigas, 1930 ; Rhigonema Cobb, 1898; Ichthyocepha- 

 lus Artigas, 1926. 



key to subfamilies of atractidae 

 I. (6) Esophagus with its parts of very different diam- 

 eters. 



