Chris has it with 'Edison Phonograph Key', also know as a'Dolphin Key'.
This style came in at least seven different sizes, ranging from about 2 to 4 inches in length (Information courtesy of Leslie Rosenfeld).
There is another Edison key with two rams butting heads. This key was used with higher-priced Edison Disc Phonographs like the A290, 375 and 425." "Edison was trying to improve the telegraph transmitter when he noticed that the movement of the paper tape through the machine produced a noise resembling spoken words when played at a high speed.
Experimenting with a stylus (hard-pointed instrument like a large needle) on a tinfoil cylinder, Edison spoke into the machine."