THE ROUNDWORMS OF DOMESTIC SWINE. 9 



been supplied by the creation of a new genus, Arduenna, by Railliet 

 and Henry (1911), Spiroptera strongylina being taken as the type. 

 Both Arduenna and PJiysocephalus, together with Simondsia paradoxa, 

 belong in the family Filariidse, 1 and are included by Railliet and 

 Henry (191 Ib) in the new subfamily Arduenninae. 



FAMILY FILARIIDSE, GLAUS, 1885. 



FAMILY DIAGNOSIS. Nematoda: Body long, filiform. Mouth surrounded with 

 papillae, or provided with two lips. Esophagus slender, without posterior bulb. 

 Males with a single spicule or with two unequal spicules. Females with two ovaries; 

 vulva usually in front of the middle of the body. Usually ovoviviparous. Develop- 

 ment in many cases requires an intermediate host. 



TYPE GENUS. Filaria Muller, 1787. 



Subftmaily AJIDTJENNIN^E Railliet tmd Henry, 1911. 



SUBFAMILY DIAGNOSIS. Filariidae: Mouth with two lateral lips leading into a 

 pharynx marked with cuticular ridges in the form of spirals or rings. Spicules 

 unequal, the longer several times the length of the shorter. Four pairs of preanal 

 papillae. Eggs containing embryos when oviposited. 



TYPE GENUS. Arduenna Railliet and Henry, 1911. 



Genus ARDUENNA Railliet and Henry, 1911. 



GENERIC DIAGNOSIS. Filariidee: Body subcylindrical, attenuated anteriorly, 

 posteriorly somewhat broader, usually curved in a semicircle, marked by a narrow, 

 longitudinal cuticular wing on the left side, extending nearly the length of the body. 

 Cuticle densely striated transversely. Mouth with two lateral lips, each lip with 

 three lobes, leading into a small buccal capsule containing two lateral teeth, and fol- 

 lowed by a cylindrical pharynx marked with cuticular ridges forming a series of spirals. 

 Esophagus continuous, gradually broadening posteriorly and occupying from one- 

 fourth to one-third of the body length. Caudal end of the male curved in a single 

 turn. Bursa asymmetrical, the right bursal wing being broader than the left wing, 

 furnished with five pairs of stalked papillae asymmetrically arranged, of which one 

 pair is preanal, three pairs are adanal, and the fourth pair is postanal. Bursal mem- 

 brane marked with longitudinal and transverse striae, giving it a wrinkled appearance. 

 Anus surrounded by a cuticular thickening, serrated on the outside edge. Spicules 

 long and very unequal, the longer five to seven times the length of the shorter. Vulva 

 anterior of the middle of the body. Eggs with thick shells containing embryos at the 

 moment of oviposition. Parasitic in the stomachs of Suidse. 



TYPE SPECIES: Arduenna strongylina (Rudolphi, 1819), Railliet and Henry, 1911. 



Diesing (1861a) proposed the family name Spiruridea for a group of nematodes distinguished from 

 FUaria by the curl or spiral twist of the tail of the male. This family is not accepted by most recent writers 

 on the ground that it is not based on sufficiently characteristic morphological features, and that the name 

 does not conform to the rules of zoological nomenclature. Oerley(18S5a), Leiper (1908), and Railliet and 

 Henry (1911b) use the name Spiraridae, apparently modifying Diesing's (1861a) family name Spiruridea 

 to conform to the present zoological nomenclature. The family name Spiropterldae Is proposed by Leroer 

 (1911). 



Owing, however, to the apparent invalidity of the name Spiroptera, the present writer prefers not to use 

 either the family name Spiruridse or Spiropteridse, and although it is evident that the genera Arduenna 

 and PJiysocephalus, and other genera as well, will ultimately be separated from the Filariidse, it is not con- 

 sidered desirable to attempt such a revision until a more careful study has been made of the various species 

 involved. In the present paper, therefore, A rduenna and Physoccphalus are retained in the family Filariidse 

 but included under the subfamily Arduenninse, Railliet and Henry, 1911. 



52865 Bull. 15812 2 



