_Filaria hominis oris_, Leidy.--In the fifth volume of the ‘Proceedings of the Philadelphia Academy of Natural Sciences’ (1850, p. 117) Dr Leidy furnishes the following description of this worm as gathered from the examination of a simple specimen preserved in alcohol, and labelled as having been “obtained from the mouth of a child.” Body white, opaque, thread-like; mouth round, simple; posterior extremity obtuse, furnished with a short, curved, epidermal hooklet, 1/500″ in length, by 1/2000″ in diameter at base. Dr Leidy offers some speculations as to its origin, but from whatever source the worm was obtained by the bearer, it seems to be an immature form. Its length is five inches and seven lines. _Filaria_ (_Nematoideum_) _trachealis_, Bristowe and Rainey.--This is another very doubtful worm. It was originally described in the ‘Pathological Society’s Transactions’ for 1855. It evidently represents only a juvenile stage of growth of some species of round worm. Rainey discovered a considerable number of these worms in the trachea and larynx of a person who died from a disease affecting the lower extremities. Individually the parasites measured about the 1/50″ in length. _Strongylus_ (_Filaria_) _bronchialis_, Rudolphi.--This is a small nematode. The male measures rather more than half an inch, whilst the female is upwards of an inch in length. The caudal appendage of the male is furnished with a bilobed, membranous, half-bell-shaped bursa. This surrounds the cloacal outlet, the latter concealing a double spiculum. The tail of the female is sharply pointed, the anal orifice being placed a little in front or above. The body is filiform, of a pale yellow color. It is about 1/50″ broad in the male, and 1/35″ in the female. The mode of reproduction is viviparous. The original specimens were discovered by Treutler in Germany, during the winter of 1791, in the bronchial glands of an emaciated subject, whilst those sent to Diesing for description were discovered by Dr Fortsitz at Klausenberg, in Transylvania, in the lungs of a boy six years old. Diesing and Weinland suggested the identity of _Filaria bronchialis_ and _Strongylus longevaginatus_, whilst Küchenmeister went further, and pronounced them to be one and the same species. BIBLIOGRAPHY (No. 27).--_Cobbold_, ‘Entoz.,’ p. 357.--_Davaine_, ‘Synops.,’ l. c., ‘Synopsis’ cix.--_Küchenmeister_, l. c., Eng. edit., p. 381.--_Leuckart_, l. c., s. 618.--_Treutler, F. A._, “De vermibus filiformibus (_Hamularia lymphatica_) in glandulis conglobatis bronchiorum repertis,” in ‘Obs. Pathol. Anat.,’ 1793.--_Wedl._, ‘Die im Menschen vorkommenden Helminthen’ (quoted by Leuckart), Wien, 1862, s. 22.