Chologaster papilliferus detects its food entirely by the sense of touch. Two which were kept in an aquarium for over a year were starved for a few days. They became very nervous, continually swimming along the sides of the aquarium. Asellus was introduced. These, even if quite near, produced no effect if moving in front of the Chologaster. The moment one came in close proximity to the fish from any direction, by a flashlike motion it was seized. None of them were swallowed. The fish became very alert after the introduction of the sowbugs, and when swimming forward would strike at a part of a leaf if it came in contact with the head of the fish. It seemed evident that the eye gave no information of the character of the object. As Asellus was not altogether to their taste, Gammarus was introduced. One of these swimming rapidly toward the chin of the Chologaster from behind and below was instantly seized when it came in contact with the fish. The eye could not have located the Gammarus at all. The action is in very strong contrast to the action of a sunfish, which detects its food by the sight. It is undoubtedly this peculiar method of locating and securing food which has enabled the Amblyopsidæ to establish themselves in caves. The Chologaster in general make-up is like Amblyopsis, but is somewhat longer-jointed. It sits with its pectorals extended. When it moves horizontally for some distance the pectorals are usually pressed to the sides, the propelling being done largely by the tail very much after the manner of a salamander, which it resembles. In swimming toward the surface it uses its pectoral fins chiefly, and the fish usually sinks to the bottom as soon as its efforts to raise itself are stopped. Individuals kept in aquaria with one end darkened either collected in the darkened area floating about, or under leaves or sticks in any part of the aquarium. They are frequently found under a floating board, where they float with the tops of their heads in contact with the board, their bodies slanting downward. They seek the dark, regardless of the direction of the rays of light. These characteristics they have, in great part, in common with the blind members of the family. The adult Amblyopsis frequently floats with its head to the top of the water, the tail sloping downward, and in swimming along ledges of rock the top of the head is applied to the ledge. I have captured many specimens simply by scraping my net along the surface of a ledge. Typhlichthys, living in total darkness, has retained the habit of staying under floating boards, sticks, and stones. Miss Hoppin noticed that Troglichthys swims with its back to the sides of the aquarium, and I have repeatedly noted the same in the young of Amblyopsis up to fifty millimetres, and the still younger Amblyopsis frequently hides under rocks.