Is there a direct bus from HK to Xiamen? How much is the fare? Where is the bus station?

I heard there is direct bus from HK to XM and the fare is 310RMB. But I only know where to board in XM, but not know the board position in HK.
From HK, it is suggested to go to Luohu Shenzhen. There you can find Qiaoshe Bus Station where you can find buses to reach XM.