THE KOUNDWORMS OF DOMESTIC SWIXE. 21 



The specimens described by Von Linstow were from the stomach 

 of Sus cristatus at Chilaw, Ceylon, and are deposited in the museum 

 of Colombo. Railliet and Henry (191 Ib) identify with Von Linstow's 

 (1904f) Spiropteradentata certain parasites collected from the stomachs 

 of pigs slaughtered at Hue", Annam Province, Indo-China, and include 

 them in the genus Arduenna. The specimens examined by Railliet 

 and Henry (191 Ib) differ, however, from Von Linstow's (1904f) de- 

 scription in the position of the vulva and the length of the spicules. 

 According to the former authorities, the position of the vulva is diffi- 

 cult to observe, but the spicules measure 3.75 to 4.23 mm., and 540 to 

 650 fj., respectively. 



The principal differences between Arduenna dentata and Arduenna 

 strongylina are the greater size of the former and the fact that the 

 chitinous ring surrounding the cloacal opening, described for Arduenna 

 strongylina, forms an almost complete circle in the case of Arduenna 

 dentata, while in Arduenna strongylina it includes only the posterior 

 and left sides. Railliet and Henry's measurements for Arduenna 

 dentata are: Males: 25 to 35 mm. long by 700 to 800 //broad; females: 

 40 to 55 mm. long by 1.1 to 1.2 mm. broad. 



Genus PHYSOCEPHALUS Diesing, 1861. 







GENERIC DIAGNOSIS. Filariidse: Body elongated, subcylindrical, slightly tapering 

 anteriorly. Head marked off from the rest of the body by a cuticular inflation ending 

 abruptly in a circular line a short distance anterior of the posterior end of the pharynx. 

 Extending from the base of the cuticular inflation to about the middle of the body 

 are 6 lateral cuticular wings, 3 on each side, the middle wing of each 3 being broader 

 than the other two. Mouth with 2 trilobed lips, with a rounded papilla on each lobe, 

 and leading into an inconspicuous buccal capsule without teeth. Pharynx relatively 

 long and broad, marked by prominent ridges forming both spirals and simple rings, 

 and extending the length of the pharynx on the inside. Tail of the male twisted 

 spirally, furnished with a narrow symmetrical bursa supported by four pairs of preanal 

 papillae. Spicules long and unequal, the left spicule about five times the length of 

 the right spicule. Vulva somewhat posterior of the middle of the body; eggs smooth, 

 with thick shells, containing well-developed embryos at the moment of oviposition. 

 Endoparasitic in the stomach of suidae. 



TYPE SPECIES. Physocephalus sexalatus (Molin, 1860) Diesing, 1861. 



Physocephalus sexalatus (Molin, 1860) Diesing, 1861. 



1860: Spiroptera sexalata Molin, 1860b, p. 957. 



1860: Spiroptera strongylina suis labiati: Molin, 1860b, p. 957 



(Museum label). 

 1861: Pfiysocepfialus sexalatus (Molin) Diesing, 1861 a, p. 686. 



SPECIFIC DIAGNOSIS. Physocephalus: Head about 60 ji in diameter at the anterior 

 end, furnished with 2 tiilobed lips, each lobe being ornamented with a thick, rounded 

 chitinous papilla (fig. 15). The cuticle of the head, extending from the mouth to a 

 point 232 p from the anterior end, ia more or less inflated. Pharynx cylindrical, 263 



