base. There are two slender and unequal spicules projecting from one of the specimens. The cuticle is not obviously striated, but is dotted over with a number of widely scattered, nearly hemispherical, smooth bosses, springing abruptly from the surface. There appears to be no definite arrangement of these bosses; at all events, if they are arranged after a pattern this could not be discerned. The larger bosses are found towards the middle of the parasite; at the head and tail they are considerably smaller, and in these situations they are more sparingly distributed. The larger measure at the base 0·12 mm., and rise about 0·004 mm. above the general surface. The extreme ends of the parasite are not provided with bosses, the first met with being about 1·5 mm. from the mouth and tail-tip respectively. “Owing to the opacity of the specimens the details of the internal structure cannot be made out. In one worm, as mentioned, a short pharynx can be seen, but its continuation into the œsophagus cannot be traced. The prolapsed testicular and alimentary tubes in one of the specimens are collapsed and ribbon-like; they are about 0·09 mm. in breadth. “The following diagram roughly indicates what I conceive to be the arrangement of the details of the under surface of the tail.” [Illustration: FIG. 6. Diagrammatic.] In endeavouring to ascertain how the parasite entered the system I inquired as to the water and food supply at Old Calabar, and my patient informed me that at Iköröfiön, the mission station at which she resided, the entire water-supply during the dry season was obtained from a spring that bubbled up out of the ground close to the river. During the rains, however, this spring might occasionally be covered by the swollen river, but at that season the water-supply was derived from a tank in which the rain was collected. The water used for drinking was always boiled, and twice filtered. In washing her face she was specially careful to keep her eyes well closed, and if at any time her eyes were sore she bathed them with the drinking-water. These precautions she took, as it was a popular belief among the natives that the worm gets access to the eyes through the water with which the eyes are bathed. She further informed me that the occurrence of this kind of worm in the eye is well known to natives of Old Calabar, and they use a solution of salt and water as a wash to scare them away. Mosquitos abounded at the station, and any water left standing in a dish soon swarmed with their eggs. The fruit supply consisted of mangos, Avocado pears, bananas, pineapples, oranges, and custard-apples. No uncooked vegetables were used as food.