Found the following hamletworks.org entries referring to line 3368-9

View Commentary Note for 3367-68
3367-8 Clow. A pestilence on him for a madde rogue, a pourd a | flagon of 

View Material Textual Note for 3367-68
3367-8 Clow. A pestilence on him for a madde rogue, a pourd a | flagon of 

View Commentary Note for 3368-69
3368-9 Renish on my head once; this same skull | sir, <this same Scull sir,> was {sir} Yoricks skull, the 
3369 Kings Iester5.1.181

View Material Textual Note for 3368-69
3368-9 Renish on my head once; this same skull | sir, <this same Scull sir,> was {sir} Yoricks skull, the 
3369 Kings Iester5.1.181