132 LEPIDOPTERA. 



that they all emerged typical. On the other hand, I have 

 seen the moths — also all typical — in hundreds on the top of 

 a ridge of limestone hills in Shropshire, crowding upon the 

 patches of blooming thyme. The blossoms of thistle, knap- 

 weed and various other plants are also frequented, and it 

 flies about among them in a sufficiently lively manner during 

 the sunshine. Widely distributed though always local, and 

 known to occur in Kent, Sussex, Dorset, Hants, Bedfordshire, 

 Devon, Somerset, Gloucestershire, Oxfordshire, Herefordshire, 

 Derbyshire and Shropshire, also rarely in Cheshire, Norfolk 

 and Suffolk, and rather plentifully on the eastern side of 

 Yorkshire. In Scotland the only record seems to be from 

 near Oban, Argyleshire. In Ireland the Rev. W. F. Johnson 

 has found it commonly near Armagh in company with 

 Z. trifolii, a companionship which seems hardly to have 

 been noticed elsewhere; and Lieut. J. J. Walker found it in 

 Gal way. 



Abroad it is common over the greater part of Europe, and 

 in Siberia, Armenia, and Asia Minor. 



I have described these last two species — Z. lonicercc and 

 Z. trifolii as distinct, in deference to the universal admission 

 of them as separate species, both at home and abi'oad, but 

 they are exceedingly difficult to separate in the perfect state, 

 since all their distinguishing characters, even to the form of 

 the antennae, and of the marginal stripe on the hind wings, 

 vary so as almost to merge one into the other. The larva3 also 

 are alike, so that no reliably distinctive character seems to exist, 

 and their pupa3 and cocoons are similar — though a difference 

 of habit seems apparent in the situation of the latter. But 

 the difficulty has recently been very seriously enhanced by 

 the discovery by Mr. W. H. B. Fletcher, that they not only 

 pair together with perfect freedom, but produce fertile eggs 

 from which emerge healthy larva) producing in due course 

 moths having intermediate characters, or the characters in 

 l)art of both parent races. And further, these (so-called) 



