Based on Bill Verners' Inside the Java Virtual Machine, McGraw Hill Companies, 1997

monitorenter - Enter and acquire object monitor
  opcode:  194 (0xc2)
  usage: monitorenter
  stack before: ..., objectref
stack after: ...
 
description: The top word of the operand must be a non-null object. To execute the monitorenter instruction, the Java Virtual Machine pops objectref from the stack and on behalf of the current thread enters and acquires monitor associated with objectref

monitorexit - Release and exit object monitor
  opcode:  195 (0xc3)
  usage: monitorexit
  stack before:..., objectref
stack after: ...
 
description: The top word of the operand must be a non-null object. To execute the monitorenter instruction, the Java Virtual Machine pops objectref from the stack and on behalf of the current thread exists and releases monitor associated with objectref.

multianewarray - Allocate new multi-dimensional array
  opcode:  197 (0xc5)
  usage: multianewarray array-desc num-dimensions
  stack before: ..., count1, [count2,...]
stack after: arrayref
 
description: The multianewarray instruction takes two parameters, the type descriptor for the array and the number of dimentions to allocate. The top dimensions words of the operand stack, count1, [count2,...], must contain ints that have nonnegative values.