To the above, however, may probably be added a specimen preserved in the Anatomical Collection at King’s College, London. It was found connected with an ovarian cyst. _Tænia elliptica_, Batsch.--This parasite is readily recognised not merely by its delicate form and small size, but also by the circumstance of its supporting two sets of reproductive organs in each mature joint. Their outlets are situated at the centre of the margin of each segment, one on either side. Ordinarily infesting the cat, this worm is a mere variety of the common _Tænia cucumerina_ of the dog. At all events, from the evidence put forth by Eschricht, seconded by Leuckart, there is every reason for believing that one or other of these closely-allied varieties is liable to infest the human body. It was originally stated by Eschricht that he had received a _Tænia canina_ which had been passed by a negro slave at St Thomas, Antilles. This is a synonym of _T. elliptica_, which must therefore be very rare in the human body, possibly only occurring in the negro race. In regard to the source of this parasite, it has been shown by Melnikow that the scolex of _Tænia cucumerina_ resides in the louse of the dog (_Trichodectes latus_), and thus it is exceedingly probable that the scolex of _Tænia elliptica_ resides in the louse of the cat (_Trich. subrostratus_). How man becomes infested is not so clear. Melnikow’s paper on the juvenile state of this cestode is contained in the ‘Archiv für Naturgeschichte’ for 1869, and is illustrated by a figure of the measle.