Male.—10·5 mm. long by 0·6 mm. broad. Head terminates in a globular swelling with two large lips. Neck 3 mm. broad. In front of neck eight rows of simple spines directed backwards. Anterior half of body with cuticular laminæ, posterior unarmed. Two pre-anal and two post-anal papillæ. Bursa wanting.
Spicules 1·1 and 0·4 mm. respectively.
Leiper considers Gnathostoma siamense to be identical with Gnathostoma spinigerum.
The single specimen described by Levinsen was found by Deuntzer in Bangkok (Siam), and was obtained from a young Siamese woman who suffered from a small tumour of the breast which had developed in the course of a few days. After the disappearance of the tumour, nodules the size of beans were found in the skin; out of one of these the worm was obtained. The same observer saw this affection in two other persons.
A closely related species, Gnathostoma spinigerum, Ow., lives in the stomach of wild cat (Felis catus), puma (Felis concolor), tiger (Felis tigris), and domestic cat (India); another species, Gnathostoma hispidum, Fedsch., 1839, in the stomach of pigs in Turkestan, Annam, Hungary, Congo, and by Collin in the stomach of an ox (Berlin).
Gnathostoma sp. in pariah dogs, Calcutta. Gnathostoma sp. in monkeys, French Guiana. They produce large fibrous thickenings in the stomach wall.
Gnathostoma spinigerum, Owen, 1836.
Cuticle of bulb with eight rows of chitinous laminæ with their posterior edges notched into spines. The laminæ on the anterior portion of the body are similar trident laminæ. In the middle of the body, the laminæ are simple and conical, cuticle posteriorly is unarmed. Mouth with two fleshy lips.
Male 5 mm. long by 0·5 mm. broad; tail spiral, four pairs of papillæ.
Female about twice as long; tail straight, trilobed.