Which one of those is supposed to be an SSD icon? Top row we have, from left to right, generic external drive, an optical disk drive, time machine, icloud, shar

Which one of those is supposed to be an SSD icon? Top row we have, from left to right, generic external drive, an optical disk drive, time machine, icloud, shared (network) drive, CD. Bottom row we have three types of floppy disks, a Sony MemoryStick, a CompactFlash, and and SD card. There's no SSD icon.