The rows before the instruction "continue in pattern" should explain exactly what the pattern is. Or possibly there is a section at the beginning of the instructions that tells you what the repeat pattern is. Those are the directions to follow for pattern on the WS.
As you continue in this pattern, you'll be working fewer sts every 2 rows. So work the given number of sts, turn as you would at the end of the row and work back on that same number of sts. I'm guessing that the two numbers (36-40, 34-38, and 31-35) are possibly for two different sizes?
What is the name of this pattern and perhaps we can find it or find a picture of it?