cuticular ring. A narrow keel-like edge of cuticle extends along either side of the hody. The two spicules are solid chitinons rods. The medial papillae number over 24 pairs; there are at least 5 pairs of postanal papillae.
Ankylostomum duodenale, Dubini, 1843
Synonyms.—Anchylostomwn duodenale; Agchylostoma duodenale; Anchylostoma duodenalis; Strongyluts duodenalis; Dochmius duodenalis; Uncinaria duodenalis.
Ascaris lumbricoides, though an unpleasant parasite, cannot be considered a dangerous one, unless in very exceptional circumstances. It is otherwise with the ankylostomum; this, in many tropical countries, on account of the dangerous cachexia to which it gives rise, called ankylostomiasis, amounts to a positive curse.
Nomenclature.—The form of endemic anaemia with which this parasite is associated is of so marked a character that it has received a variety of distinctive names. Thus, in the French West Indies severe ankylostomiasis is known as cachexie aqueuse; sometimes as malcceur, or as mal d'estomac des negres; in Colombia it is called tuntun, the sufferers being known as tunientos; in Brazil it has been called oppilatio, opilaqao, and canqapo; in Europe it is sometimes known as " miner's anaemia," or " tunnel disease," the latter in allusion to the notorious St. Gothard epidemic; the form occurring in Egypt is spoken of as Egyptian chlorosis; in Ceylon it has been called "beriberi," a name which has not infrequently caused confusion with true beriberi; and, doubtless, elsewhere there are local names for this peculiar verminous anaemia.
Geographical distribution.—Since its discovery by Dubini, in 1838, the ankylostomum has been found so widely diffused that it may be said to occur in all tropical and sub-tropical countries. It occurs in Belgium, and a few years ago was found by Prof. Haldane to be the cause of an epidemic of severe anaemia in a Cornish mine. In northern countries it is rare; but it is abundantly present in the south of Europe, and in the tropical and sub-tropical regions of Asia and America; it has been
