TRIFIDAL. 117 



hollowed below the apex ; cloudy-white, the costal margin 

 and some portion of the basal area quite white or streaked 

 with the same ; rest of the wing more or less clouded with 

 smoke-coloiir ; in the middle is a faintly darker smoky 

 transverse stripe, usually very obscure or hardly perceptible, 

 cilia white. Female larger, often much larger, with thread- 

 like antennas, and stout, almost unwieldy body, but the anal 

 tuft small ; otherwise similar. 



Underside of the fore wings whitish-drab dusted with 

 black, but with a large smoky cloud occupying the middle 

 portion, and a faint cloudy-black indication of a reniform 

 stigma. Hind wings white dusted with brown ; on the hind 

 margin below the apex are two or three black dots. Body 

 and legs brownish-white, but the tibite rather blackened. 



Rather variable in colour, from the palest drab to various 

 shades of pale red-drab ; often with smoky-brown clouds 

 along the principal nervures in lieu of the dusting ; occasion- 

 ally in the more darkly shaded individuals one or two faint 

 black dots will appear on nervures, or one on the dorsal 

 margin, suggesting the place of the usual first line. In the 

 cabinet of Mr. R. Adkin are two specimens of a terra-cotta 

 red, the colour of Nonagria cannce, but more glossy. There 

 is also a remarkable variation in size ; some of those of both 

 sexes and of all the shades of colour being of little more than 

 one-half the expanse of the largest-sized females. This form 

 was first observed in the Isle of Wight, and received the 

 name of Vectis, being supposed to be a distinct species. 

 With this are found all the intermediate gradations of 

 size. It seems to occur in ditches where the reeds are but 

 small. 



On the wing from the end of July or beginning of August 

 till October, and occasionally even to November or the 

 beginning of December. 



Larva soft and excessively wrinkled, with a raised ridge 

 of wrinkled skin down each side ; of nearly even width ; 



