Linguatula, body flattened, but dorsal surface arched; the edges of the fluke-like body crenelated; the body-cavity extends as diverticula into the edges of the body.
Porocephalus, body cylindrical, with no diverticula of the body-cavity.
Reighardia, devoid of annulations, transparent, with poorly developed hooks and a mouth-armature.
The following is a list of the species with their primary and secondary or larval hosts:—
i. Linguatula pusilla, Diesing, found in the intestine of the fresh-water fish Acara, a South American genus of the Cichlidae. This is possibly the immature form of L. subtriquetra.
ii. L. recurvata, Diesing, found in the frontal sinuses and the trachea of Felis onca.
iii. L. subtriquetra, Diesing, found in the throat of Caiman latirostris and C. sclerops, perhaps the mature form of L. pusilla.
iv. L. taenioides, Lamarck, found in the frontal sinuses and nasal chambers of the dog and ounce, and in the nasal cavities of the wolf, fox, goat, horse, mule, sheep, and man, and in the trachea of the ounce. The immature form has been found in or on the liver of the cat, guinea-pig, and horse; in the lungs of the ox, cat, guinea-pig, porcupine, hare, and rabbit; in the liver and connective tissue of the small intestine of man; and in the mesenteric glands of the ox, camel, goat, sheep, antelope, fallow-deer, and mouse.
v. Porocephalus annulatus, Baird, found in the lungs of the Egyptian cobra, Naja haje; the immature form is thought to live encapsuled in a species of Porphyrio[[391]] and in the Numidian Crane.
vi. P. aonycis, Macalister, from the lungs of an Indian otter taken in the Indus.