Porocephalus armillatus (Wyman, 1848)
Synonyms.—Linguatula armillata; L. constricta; Pentastomum constrictum; P. polyzonum; P. diesingi; P. euryzonum; Nematoideum hominis.
History.—The larval form of this vermiform arthropod, belonging to the family Linguatulidæ, genus Porocephalus, was discovered in 1847 by Pruner, who found it, in Cairo, in the livers of two negroes. It must have been found in man before that date, since Pruner himself informs us that he saw two specimens in the Pathological Museum of Bologna, labelled "Insects from the liver of man." Subsequently it was found in man by Bilharz, Fenger, Kearney, Crawford, Marchoux, Chalmers and others. In 1852 von Siebold proposed to call it Pentastomum constricium; but Shipley, in his revision of the family Linguatulidæ (1898), points out that the adult form was discovered and named Linguatula armillata in 1848 by Wyman, who found it in the lungs of an African python. Shipley further considers that Hoyle's Pentastomum protelis from the aardwolf (Proteles cristata), Wedl's P. leonis from the lion, Van Beneden's P. diesingi from the mandrill (Cynocephalus mormon), and Hartley's P. polyzonum from an African python, belong to the same species. He also states that, in accordance with the rules of zoological nomenclature, the generic name for the cylindrical Linguatulidæ should be Porocephalus, a term introduced by Humboldt eight years before Rudolphi proposed the name Pentastomum. Neumann (1899) refers the larval forms found in man to Porocephalus moniliformis, a species discovered by Diesing in 1836 in the Indian python (Python molurus). Looss (1905) is of opinion that Wyman's and Diesing's species are identical. Sambon agrees with Shipley's determination, based principally on the number of rings, which are never more than 22 in P. armillatus, but 28 to 30 in P. moniliformis.
Fig. 166.—Porocephalus armillatus, natural size. (After Sambon.)
Geographical distribution.—P. armillatus seems to be confined to tropical Africa, and hitherto, as regards man, to negroes only, among whom it is far from being uncommon. Dr. Salm has found a porocephalus encysted beneath the serous coat of the small intestine of a Djambi native in Java. He gives no description, but mentions it under the name
