In the San Juan Islands the otters have taken to a marine existence. In the summer of 1938, abundant opportunity offered to observe the otters at Thatcher Bay, Blakely Island. Here, in the evening, bats were shot as they flew over the calm water of the bay. Specimens killed were retrieved by rowing out to them with a dory. For the first two nights bats were collected and retrieved without incident. On the third night, several of the bats vanished between the time they were killed and the time that the boat was launched from the rocky beach. The presence of a shark or other large fish was at first suspected, but observation showed a group of three or possibly four otters to be the thieves. On succeeding nights the animals became bolder. A dead bat became the object of a race between otters and collector. They completely ignored shouts, dodged stones hurled at them, and stole almost all the bats shot. Only a sense of humor and desire to study the animals saved them from a load of fine shot. Bat collecting was given up in disgust. These otters were remarkably seallike in many actions. In swimming their heads, shoulders and part of their back were exposed. In resting in the water, only the round head remained above the surface. They were never seen to float prone on the surface or rest on their backs, as does the sea otter. They were noisy swimmers, splashing with paws or heads as they dived. Their eyesight was remarkable. Stones the size of a walnut were hurled at them from distances as short as 25 feet. All were dodged with little effort. In this connection the experience of two trappers who caught an otter in the Samamish River near Woodinville, King County, is interesting. The trap holding the otter had been attached by a wire 6 feet long to a pole on the bank. The wire was detached from the pole; while one trapper held the wire, the other tried to strike the otter with an oar as the boat drifted over deep water. The otter was free to swim and dive for the length of the wire and trap chain. It detected, and evaded by dodging or diving, every blow directed at it and not until the animal tired, a half hour later, could it be killed. The trappers then noted that the splashing of oars and otter had nearly filled the boat with water. The trappers were exhausted.