Acopa (akopa)

pl. [NL., These two cla es were formerly separated according to whether they had or had not a propelling tail, as the names of the cla es showed. I have retained the nomen clature without giving an importance to this character which does not belong to it; the larvæ of many Acopa have the directive organ. A much greater difference between the two divisions is to be found in the characters of their spiracles. In the Copelata these open on to the exterior. In the Acopa they open into a cavity, which is formed from a part of the rudimentary spiracle of the Copelata. Gegenbaur, Comp. Anat. (trans.), p. 389. 2. [sing.] A genus of lepidopterous insects.