THE ROUNDWORMS OF DOMESTIC SWINE. 39 



Section. 



8. Male with two equal or subequal spicules; tail with membranous bursa sup- 



ported by paired rays and eggs with thin shells 9 



Male with two spicules of very unequal length; tail with lateral longitudinal 

 bursal membranes supported by stalked pappillse. Eggs with thin or thick 

 shells 12 



9. Mouth enlarged to forma buccal capsule 10 



Mouth small; buccal capsule not present. Male 5 mm. long. Female 8 to 8.5 



mm. long. Spicules 130 /j. long. Vulva about 2 mm. from the tip of the 

 tail. Eggs, 45 fi long by 36 (JL wide. In stomach "Strongylus" rubidus. 1 



10. Buccal capsule broader than long, mouth bordered by a crown of numerous, 



small, pointed processes. Male 8 to 12 mm. long. Female 12 to 15 mm. 

 long. Spicules slender, 1.13 mm. long. Vulva a short distance in front of 

 anus, piptuberant. Adults in large intestine, larvae encysted in the wall 

 of the large and small intestines, forming nodules. .(Eesophagostomum dentatum. 

 Buccal capsule spherical or elongated , border of mouth smooth 12 



11. Buccal capsule spherical. Male 7 mm. long, 0.2 mm. thick. Female 8 mm. 



long, 0.3 mm. thick. Vulva prominent. In small intestine. 



Globocephalus longemucronatus. 



Buccal capsule elongated, oval. Male 4.4 mm. long, 0.38mm. thick. Female 

 6.5 mm. long, 0.52 mm. thick. Spicules 590 /t long. Vulva sunken. In 

 small intestine Crassisoma urosubulatum. 



12. Anterior end of body supplied with numerous cuticular tubercles or shields. . 13 

 Anterior end of body without cuticular tubercles 14 



13. Male 30 to 50 mm. long by about 250 /JL thick. Female 80 to 145 mm. long, 



300 to 350 fjL thick. Left spicule 16 to 17 mm. long; right spicule 140 to 180 fj. 

 long. Vulva 4 to 5 mm. from tip of the tail. Eggs 55 to 60 ft long by 32 to 

 36 [i wide. In the mucosa of the esophagus and pharynx. 



Gongylonema scutatum. 2 



Male 14 to 50 mm. long, 175 to 195 fj. thick. Female 37 to 40 mm. long (? or 

 longer), 350 n thick. Left spicule 4 to 5 mm. long, right spicule 84 to 110 

 fj. long. Vulva about 2 mm. from the tip of the tail. Eggs 52 to 56 , long 

 by 32 fj. wide. In the mucosa of the esophagus and pharynx. 



Gongylonema pulchrum. 



14. Body furnished anteriorly with six longitudinal lateral wings, three on each 



side, the middle wing of each three wider than the other two. Ridges of 

 pharynx forming a simple spiral, breaking up into separate wings. Male 

 6 to 9 mm. long. Female 13 to 19 mm. long. Spicules 2.1 to 2.25 mm . long, 

 and 300 to 350 /t long, respectively. Vulva anterior of the middle of the 

 body. Eggs 34 u. long by 15 , wide, with rather thick shells. In stomach. 



Physocephalus sexalatus. 



Anterior portion of body with a single longitudinal wing. Ridges of pharynx 

 forming a continuous multiple spiral 15 



1 "Strongylus" rubidus does not belong in the genus Strongylus. Its proper position is in the family 

 Trichostrongylinse. As yet, however, no genus has been established to which it may be assigned. 



* Reported by Korzil (1877a) and Piana (1896b). According to Neumann (1894d), however, the measure- 

 ments given by Korzil indicate that the species studied by him is Gongylonema pulchrum, Molin 1857. 

 The measurements given by Piana(1896b) are, males 60 to 80 mm. long by 130 ft broad; females 80 to 145mm. 

 long, 600 n broad. Except that G. pulchrum is smaller than G. scutatum, there is but little morphological 

 difference between the two species. The species are considered identical by Railliet (1893a), although this 

 view is not accepted by Neumann (1894d) and others. G. scutatum is normally a parasite of ruminants. 



