THE ENTOMOLOGIST. 



Vol. L.] APRIL. 1917. [No. 647 



A NEW GEOMETEID MOTH. 

 By the Rev. J. W. Metcalfe, F.E.S. 



In response to my friend, Mr. F. N. Pierce's challenge in 

 last month's ' Entomologist,' I gladly give at once some particu- 

 lars concerning the new Geometer exhibited by Mr. Newman at a 

 meeting of the South London Entomological Society, and 

 reported to have been captured by myself. This was not the 

 first occasion on which the insect had been exhibited, and the 

 previously expressed view that it was only a race of the variable 

 C. suffamata led me to suppress my own opinion to the contrary 

 until such time as it should receive further confirmation. 



This has now been supplied through the kindness of. Mr. 

 Pierce himself, who has enabled me to examine critically his 

 mounts of the genitalia. As might be expected, the genitalia, 

 though much smaller, show a close similarity to those of suffu- 

 mata, but at the same time such definite and constant differ- 

 ences as to leave no doubt but that we have here a distinct 

 species. The chief points to notice are that in the c^ the anellus 

 lobes are much stouter and shorter, while the basal parts of 

 these lobes, from which the loug hairs spring, are of quite a 

 different form. In the ? the shape of the ostium is markedly 

 different. Mr. Pierce is himself satisfied that their differences 

 justify the opinion I had formed on other grounds, that we have 

 here two species. 



I will now give particulars as to the facts which led me to 

 form that opinion. I first captured the insect some ten Aears 

 ago, flying in considerable numbers, in a remote locality iu 

 North Devon. The striking difference in the shape of the wings 

 from those of suffumata, the small size, and the shining, silvery, 

 ground-colour, at once attracted my attention. A subsequent 

 visit led to further captures, and on coming to live in East Devon 

 I was delighted to discover it agam in a similar locality in this 

 part of the county. In addition to this, Mr. Newman has now 

 found a series in a collection made in Cornwall, where he reports 

 that it was taken under similar conditions. 



The species seems to be absolutely constant in form, and in all 

 specimens I have taken, well over a hundred, there has not been 



ENTOM. — APRIL, 1917. G 



