Two types of nematocytes were commonly found in the fishing tentacle ofCyanea capillata. One cell contained an unencysted thread coiled about its expanded proximal butt. This thread had barbs on its surface and was enclosed within a multilayered capsule. A nematocyst enclosing a thread with an expanded terminal bulb was also present. The coils of these threads were free in the cytoplasm. No barbs were present on these structures.