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NEMA THELMINTHES 



Gnathostoma Owen, 1837. 

 Synonyms.- — Cheiracanthus Diesing, 1839; Liorhynchus Rudolphi. 

 Definition. — With the characters of the family. 

 Remarks. — ^The genus comprises only intestinal parasites, of 

 which nine species are known in man, alligators, cats, tigers, pigs, etc. 



Gnathostoma spinigerum Owen, 1837. 



Synonyms.^ — -Cheiracanthus siamensis Levinsen, 1889; Gnathostoma 

 siantense Levinsen, 1889; Cheiracanthus robustum Diesing, 1839. 



Remarks.- — ^Only two specimens are known, one a female, which 

 was obtained by Deuntzer from a young Siamese woman in whose 

 breast a hard painful swelling had formed, accompanied with slight 

 fever, and another a male described by Leiper. Nodules the size 

 of beans appeared in the skin, from one of which the worms were 

 extracted. Two other similar cases have recently been reported. 

 Leiper has recently compared a male specimen from man with 

 typical specimens of G. spinigerum of the tiger, and declares them 

 to be identical. 



Morphology— Ma/g. — 10*55 millimetres long by 0'6 millimetre broad, with 

 the anterior half of the body quite straight and terminating in a globular 

 swelling, which carries two large fleshy lips which guard the mouth. Neck 

 only 0'3 millimetre in diameter. In front of the neck the cuticle is provided 

 with eight transversed rows of chitinous hooks with their points directed 

 backwards. Behind the neck the cuticle has many cuticular laminae, but 

 the posterior half of the body is without armature. 



The mouth is simple, without a vestibule. The paired labial glands open 

 on the lips already mentioned. The oesophagus is 2*4 millimetres long and 

 very muscular, and opens into the chyle intestine, which, being uniformly 

 0-25 millimetre broad, is with difficulty separated from the rectum, which 

 leads to the cloaca. 



There are two pre-anal and two post-anal large nipple-like genital papillse 

 around the cloaca, and though the cuticle is folded there is no bursal forma- 

 tion; but there are two unequal spicules, i*i millimetres and 0*4 millimetre 

 long. There is a distinct muscular ejaculatory duct, i'5 millimetres long. 



Female. — Nine millimetres long by i millimetre broad, with eight rows of 

 bristles around the head, and spines covering the anterior third of the body. 

 Each spine ramifies into three points, of which the middle is the longest. 

 The anterior end was narrow, and the mouth appeared to be bordered by 

 two lips. The posterior end had a three-lobed prominence, at the base of 

 which the anus opened. 



Habitat. — Subcutaneous tumours in man in Siam. Allied species 

 live in the stomach of pigs and oxen. The species is said to occur 



in the pariah dogs of CalcuLia. 



Pathogenicity. — ^Man is apparently an aberrant host, for in man 

 only do the worms wander into the connective tissue and form 

 subcutaneous tumours. The species normally lives in the stomach 

 of animals, causing hbrous thickenings. 



Family 5. Physalopterid^. 

 Physaloptera Rudolphi, 181 9. 

 Physalopteridae possessing mouth with usually two lips, each with 

 papillae and teeth. Posterior end of the male lancet-shaped, owing 



