HYDRIOMRNA FUKCATA (lIYPSIPKTES SORDrDATA). 87 



I only add, iu connection with this tabulation, that probably the 

 really red forms should be separated from Nos, 5 and 6, and that our 

 ordinary whitish banded forms ought to be denoted by such " long- 

 winded " titles as sorilidata-albifasciata, etc., according to the ground- 

 colour ; it seems unreasonable to suggest a different name for each of 

 these sub-varieties, and yet their effect is so very distinct, that it hardly 

 appears right to ignore them. Guenee's var. B is to be referred here. 

 ( To be continued J. 



Notes on the Zygasnides. 



I. — General remarks on the genus Zyg^na. — Zyg^na lonicer.e a con- 

 stant SPECIES. — Hybrid Zyg^enid^. — Have we three five-spotted 

 British species (exclusive of Z. exulans and Z. meliloti) in 

 Britain ? — Are Z. hippocrepidis, St., and Z. filipendul.e distinct 

 British species ? 



By J. W. TUTT, F.E.S. 



This is meant to be a tentative paper, and is written in the hope 

 that it may lead to observations being made during the approaching 

 summer, and to the record of new facts. We do not by it invite 

 opinions, of which there will doubtless be many ; but we do hope it 

 will lead to the making of an attempt, by exact observation, to clear up 

 the present hopeless confusion that exists about some of our British 

 species of this genus. 



In previous papers we have attempted to solve some of the 

 difficulties relating to certain Zyg^nid species, ri-., Z. viinos ( Knt. 

 Eec., vi., pp. 270-276), Z. exulans {Ent. Bee, v., pp. 258-267), Z. 

 carniolica, Z. achilleae, Z. transalpina, Z. medica(/inis and Z. oclisen- 

 liebneri I Papers on the Zijijaenidae, 1894). The notes relating to 

 Z. niedicat/inis and Z. ochsenheiineri are particularly important to 

 British lepidopterists, because the first has been erroneously considered 

 an Alpine form of Z. trifolii, and the name of the latter Alpine species 

 has even been introduced into our magazines as a British form of Z. 

 Jilipendulae. We simply mention these as we do not intend to traverse 

 the ground already covered. 



The genus Zi/gaena is exceedingly interesting, from the facts that 

 some of the species are somewhat ill-defined, and that, in some cases, 

 the species hybridise pretty freely with each other, and produce fertile 

 progeny. The collector gets over the difficulties thus presented by 

 lumping the various forms as one species, but the student recognises 

 that if evolution be really a fact, and that new species are evolved 

 from earlier forms by modification, it is pretty certain that nature is 

 now at work on some plastic forms, and is, so to speak, developing 

 new species. We have, in the genus under consideration, this process 

 of evolution taking place before our eyes, and whether we unite all 

 the forms into one group and call it a species, and its component parts 

 sub-species, or allow each of the latter to be called a species, it is only 

 a matter of terms, and does not interfere with the scope of our 

 enquiries. 



Of the five-spotted Zyga?nids occurring in Britain, Z. exnlans 

 and Z. meliloti are the most fixed forms. Z. lonicerae is also a most 

 constant species. In all its British localities it is practically invari- 

 able and readily recognisable. There is no difference whatever in 



