Morbid Anatomy.-The foetus, whose sex was not evident externally, weighed 2902 grammes, and had a total length of 50 cms. It is unnecessary for my present purpose to give the various measurements in detail; suffice it to say that they proved that the head was disproportionately larger than the other parts, and that the girth of the body in the abdominal and pelvic regions was much less than normal. The foetus had, from the umbilicus downwards, a steadily diminishing circumference, which was manifestly due to the nature of the deformity.

EXTERNAL APPEARANCES.

The external appearances of the monstrosity, as seen from the front, are well exhibited in Plate I.; but the large size of the head is not so evident as it was at birth, for before the specimen could be photographed a good deal of the fluid had escaped therefrom. The nature of the teratological condition is seen at a glance; it consisted in the union of the lower limbs into one appendage, resembling somewhat the tail of the mythical mermaid.

The head was, as has been noted already, abnormally large; and palpation revealed the presence of a large quantity of fluid beneath the scalp. It was at first thought that the bones of the cranial vault were membranous, for no osseous structures could be felt; but this impression was corrected by the subsequent dissection. When the foetus was laid upon the side the head became elongated vertically and the surface resting upon the support became quite flat. A considerable number of dark hairs was found upon the scalp, especially posteriorly. There was evidence of an unusually large quantity of subcutaneous tissue in the face, especially in the region of the cheeks and under the chin; in fact, the palpebral fissures lay in two deep hollows, and there was what might be called a double-chin.

The eyelids were normal, but the membrana pupillaris seemed still to be present. The root of the nose was much depressed; and the nose itself was flattened out, and lay in a hollow between the two projecting cheeks. The mouth was open, and the tongue protruded slightly. The left ear was more prominent than the right, and from its meatus blood was flowing at the moment of birth.

The neck and thorax presented no anomalies on external examination. The arms were well formed, and, when hanging down by the sides, reached to the level of the flexure between the trunk and the single lower extremity. There was no syndactyly, the fingers being normal in number, size, and relations.

The small size of the abdominal part of the trunk was very evident. The stump of the umbilical cord was still attached, and measured 9 cms. in length; and in it only two vessels could be seen-an artery and a vein. The anterior surface of the abdomen