NO. 2131. NEMATODE PARASITES OF RODENTS— HALL. 179 



male. Vulva present or, less often, absent in gravid females; when 

 present, usually anterior of the middle of the body or near the mid- 

 dle, rarely near posterior extremity. Two, four, or five uteri. Ovi- 

 parous, ovoviviparous, or viviparous. Development in many cases, 

 perhaps all cases, requires an intermediate host. 



Type-family. — Filariidae Claus, 1885. 



The name given here was proposed by Weinland as a family name, 

 but it is in the form now used for the superf amily, and it was erected 

 as a superf amily by Stiles (1907). 



ANALYTICAL KEY TO FAMILIES OF FILARIOIDEA. 



1. Mouth without lips ; vulva near anterior extremity of body— Filariidae, p. 179. 



Mouth with 2 lips; or mouth without lips in forms where vulva is near 



posterior extremity of body Spiruridae, p. 190. 



Family FILAEIIDAE Claus, 1885. 



Family diagnosis. — Filarioidea (p. 178) : Body long and filiform. 

 Mouth without lips. Male with two spicules, usually quite dissimilar. 

 Vuha near the anterior extremity of the body. Adults subcutaneous, 

 in blood, or on serous surfaces. 



Type-genus. — Filaria Mueller, 1787. 



Subfamily ir'lL^RIIlST^'LE Stiles, 1907. 



Suhf amily diagnosis. — Filariidae (p. 179) : Vulva anterior, near 

 mouth. Spicules quite dissimilar. Intermediate stages, so far as 

 known, occur in blood-sucking arthropocla. 



Type-genus. — Filaria ISIueller, 1787. 



ANALYTICAL KEY TO GENERA OF FILAKIINAE. 



1. Adult forms Filaria, p. 179. 



Larval forms in the blood (collective genus) Microfilaria, i). 188. 



Genus FILARIA Mueller, 1787. 



Synonyms. — Filaraia Rudolphi. 1809; Filaire Lee, 1840; Filariu 

 T\Iagalhaes, in Silva Lima, 1877; Filoria Calmette, 1884; Folaria 

 Leidy, 1904. 



Generic diagnosis. — Filariinae (p. 179) : Caudal extremity of male 

 forms a spiral, provided with alae. Simple body, devoid of promi- 

 nent cuticular ornamentation or cervical alae. Esophagus simple, 

 without chitinous rings or spirals. 



Type-species. — Filaria martis Gmelin, 1790. 



