I was hurt. Still more of that wretched fish!But now I set myself to my task

with a will.

more of that指代哪个?

Still more of that wretched fish!

这是一个名词词组 Still more of that wretched fish = 还要继续察看那条可怜的鱼!

假如你结合课文上下文去阅读的话,你就会了解怎么样把这个名词词组扩充为一个完整的句子。I had to observe still more of that wretched fish!