Further, in connection with abnormal cestodes, I may observe that Weinland’s case of a triple-crowned Cysticercus does not stand alone, since a similar specimen is, I believe, in the possession of the Rev. W. Dallinger. This was removed from the human brain. Curious as this subject is, I cannot dwell upon it. Not only are the mature tapeworms and their Cysticerci liable to present monstrosities, but even also their proscolices or six-hooked embryos. Thus, twelve hooks were observed by Salzmann in the embryo of _T. elliptica_, and Heller also figures two embryos of _T. mediocanellata_ (_T. saginata_, Gœze) with numerous hooklets. Dujardin saw seven in a _Bothriocephalus_ embryo. Occasionally there have been errors of interpretation made by observers. Thus, Diesing has given beautiful figures of _Dibothrium hians_ in such a way as to suggest different degrees of monstrosity affecting the tail end of the strobile; but this splitting has clearly resulted from injury. Thus also, when I removed five specimens of a new cestode (_Diphyllobothrium stemmacephalum_) from the intestines of a porpoise, one of them was cleft nearly half way up the strobile. This had been done by the scissors employed in slitting up the gut; but owing to perfect contraction of the incised edges, it was some time before I discovered that the apparent monstrosity had been artificially produced. Lastly, I may add that many of the older writers were well acquainted with larval and other anomalies. Thus Rudolphi described a two-headed Cysticercus from a Lemur, and also a double-headed _Tænia crassicollis_. This worm had a tripartite body; as had likewise a _Tænia crassicollis_ of which he did not possess the head (_corpore prismatico_). Other monstrosities were described and figured by Bremser and Creplin. Pallas mentions a two-headed Tricuspidaria (_Triænophori nodulosi bicipites_), and, as already stated at p. 97, a double-headed Cysticercus has been obtained from the liver of a sheep. Before quitting the _Tæniæ_ proper, I may observe that several other species have been indicated, based on ovular and other insufficient characters. To these belong Ransom’s supposed tapeworm, and also Weinland’s _Tænia megaloön_.