When the alchemist creates a bomb, he can infuse it with cytillesh extract. Cytillesh bombs deal 1d4 points of damage, plus 1d4 points of damage for every odd-numbered level, instead of 1d6. Creatures that take a direct hit from a cytillesh bomb are sickened for 1 round per alchemist level unless they succeed at Fortitude saves. If a creature is rendered unconscious from this bomb or any other attack before it is able to remove the sickened condition, the victim loses all memory from the last hour and cannot form new memories for 8 hours. The lost and prevented memories might return later as dreams, and can be restored with a restoration spell. This discovery doesn’t stack with other discoveries that alter an alchemist’s bomb.
I ask because every other bomb discovery that uses this language indicates the type of damage or simply says it changes the damage dice.