40 THE ROUNDWORMS OF DOMESTIC SWINE. 



Section. 



15. Male 10 to 15 mm. long. Female 16 to 22 mm. long. Long spicule 2.24 U> 

 2.95 mm. in length, 5 to 6 times as long as the short spicule. Vulva some- 

 what anterior of the middle of the body. Eggs 34 to 39 p long by 20 ft wide, 



with rather thick shells. In stomach Arduenna strongylina. 



Male 25 to 35 mm. long, 700 to 800 /j. broad. Female 40 to 55 mm. long, 1.1 to 

 1.2 mm. broad. Long spicule 3.75 to 4.23 mm. long. Short spicule 540 to 

 650 ft long. Vulva three-eighths of the distance from the anterior end. 



Arduenna dentala. 



16. l Spicules about 4 mm. long, each terminated by a single hook. Vagina about 



2 mm. long. Male between 12 and 25 mm. in length. Female between 20 

 and 50 mm. in length. Vulva near anus. Eggs between 57 and 100 /t in 

 length and 39 and 73 ft. in width. In trachea and bronchi.. Atetastrongylus apri. 

 Spicules 1.5 mm. long, each terminated by a double hook. Vagina about 

 500 [i Jong. Male between 12 and 25 mm. in length. Female between 

 20 and 50 mm. in length. Vulva near anus. Eggs between 57 and 100 fi 

 in length and 39 and 72 fi in width. In trachea and bronchi. 



Mctastrongylus bremvaginatus. 



17. 2 Encysted in skeletal muscles, microscopic in size. Cysts slightly elongated, 



ovoid, long axis parallel to the muscle fibers, about 400 fi long by 250 fi broad. 



Trichinella spiralis (larvae). 



Free in peritoneal cavity, in kidneys, in ureters, in the bladder, or encysted 

 in fat of kidneys or loins 18 



18. Male under 40 mm. long 19 



Male over 12 cm. long 20 



19. Male 25 to 37 mm. long. Female 37 to 40 mm. long. Two spicules, equal or 



subequal, about 0.8 mm. long. Vulva less than 2 mm. from the tip of the 

 tail. Eggs 100 fi long by 56 fi wide, with thin 'shells. In kidneys, ureters, 

 and encysted in fat of kidneys and loins Stephanurus dentatus. 



20. Male 14 to 40 cm. long, 4 to 6 mm. in diameter. Female 20 cm. to 1 m. long, 



5 to 12 mm. in diameter. Spicule single, 5 to 6 mm. long. Vulva near the 

 anterior end of the body. Eggs 64 to 68 ft long by 40 to 44 ft wide, thick- 

 shelled, with pitted surface. In kidneys, ureters, peritoneal cavity, or 



bladder Dioctophyme visceralis. 3 



Male 10 to 11 cm. Greatest diameter, 650 fi. Tail twisted in a loose spiral 

 with a pointed end; 8 pairs of papillae, 4 preanal and 4 postanal. Spicules 

 unequal, the longer 215 ft long, 25 fi broad, with a membraneous extension 

 70 fi long. Short spicule 140 fi long, 52 ft broad. Female 20 to 21 cm. long. 

 Vulva 600 fi from the anterior extremity. Anus 300 fi from the posterior 

 extremity. Eggs ovoid, 45 by 26 ft when fully developed. Viviparous. 

 Parasitic in the peritoneal cavity Setaria bernardi. 



1 Railliet and Henry, 1911, describe a new species, Filaria bauchei, found in the "lungs "of a hog slaughtered 

 at Hud, Indo-China. The location of the parasite is not definitely known. The female alone was found. 

 It is reported as 22J cm. long, with a maximum diameter of 635 ft. The body is transversely striated, the 

 striae being 5 to 6 / apart. Mouth unarmed, funnel-shaped, the cuticle thickened at the anterior end. Anus 

 155 p. from the posterior extremity; vulva 1. 1 mm. from the mouth. 



8 GigantorhynchtLS Tiirudinaceus, although normally located in the intestine, sometimes perforates the 

 intestinal wall, in which case it may be found in the peritoneal cavity. (See No. 2 of this key, first para- 

 graph.) 



Ascaris suum may be found aberrant in various locations outside the digestive tract. Diagnostic char- 

 acters for the identification of this species have already been given. (See No. 2 of this key, second 

 paragraph.) 



* Included by Von Linstow (1878a) among the parasites of the domestic hog, but its occurrence in this 

 host is questionable. 



