n.圓口綱脊椎動物
primitive eellike freshwater or anadromous cyclostome having round sucking mouth with a rasping tongue. 原始的似鰻的淡水或淡水中產(chǎn)卵的圓口綱脊椎動物，它們有長有吮吸嘴，嘴內(nèi)有銼舌。
