222 NEMATHELMINTHES 



Key to the genera of Strongylidae here described: 



Oi Bursa well developed. 



61 Bursa without ribs ; 1 spicule 1. Dioctophyme 



6a Bursa with ribs ; 2 spicules. 

 Ci Mouth small, without teeth. 



di Male and female not permanently attached 2. Dictyocaulus 



dj Male and female permanently joined together 3. Syngamus 



C2 Mouth large, with teeth. 

 di Without oral glands. 



d Without ventral teeth but with cutting plates 4. Negator 



62 With ventral teeth 5. Anchylostoma 



d^ Two long oral glands 6. Strongylus 



Oa Bursa small ; in fishes 7. Cucullanus 



1. Dioctophyme Collet {Eustrongulus Diesing). Large worms with 

 6 prominent oral papillae; bursa without ribs; 1 spicule present; vulva 

 near foi'ward end: 1 species. 



D. renale (Goeze) {D. gigas Rudolphi) (Fig. 354). Body generally 



blood red; male 40 cm. long or less and 6 mm. thick; female 1 m. long or 



less, and 12 mm. thick; egg (Fig. 345, A) ovoid, brown, 



and about .068 mm. by .04 mm. : in the kidney of the dog 



and other domestic animals as well as rarely in man. 



2. Dictyocaulus Railliet and Henry. Mouth with 6 

 small papillae, bursa large with ribs and two spicules; 

 female genital pore behind the middle: many species. 



D. filaria (Rudolphi). Body white and thread-like, 

 from 3 to 10 cm. in length ; egg about .12 mm. by .06 mm. : 

 in the bronchi of sheep and goats, causing often a dan- 

 gerous bronchitis. 

 Fig 354 ^* rufescens (Leuckart). Body brown and thread- 



Dioctophyme ^i^^, from 18 to 35 mm. long; egg about .1 mm. by .06 

 (from"ward). nim. : in the bronchi and lungs of sheep and goats, causing 

 often pneumonia. 



3. Sykgamus von Siebold. Male permanently attached by the 

 bursa to the vulva of the much larger female, which is forward of the 

 middle, fonning together a Y-shaped object; bursa ribbed: 1 species. 



S. trachealis v. Sieb. Body red; male 6 mm. long; female 20 mm. 

 long: in the trachea of fowls, causing gapes. 



4. Necatoe Stiles. Head end narrower than body and curved 

 dorsally; mouth large, opening obliquely into a chitinous buccal capsule, 

 the dorsal portion of which is shorter than the ventral; buccal cavity 

 has ventrally a pair of prominent semilunar cutting plates or lips and 

 dorsally a pair of smaller lips and a conical tooth projecting into it; a 

 large bursa with 2 long, barbed spicules : 2 species, in man and anthropoid 

 apes. 



