100 Cincinnati Society of Natural History. 



The above observations would indicate that the mine in- 

 creases in length by approximately equal increments during 

 each larval instar; following a moult this rate is suddenly 

 increased, but continues nearly constant, very slightly increas- 

 ing each day until the next moult. A moult appears to occupy 

 between 36 and 48 hours. The amount consumed by the larva 

 is of course not measured directly by the increase in length of 

 the mine, since during the entire period, the mine is regularly 

 increased in breadth. 



Nepticula akgentifasciella, n. sp. 



Palpi black. Tuft black behind, reddish orange mixed with 

 dark brown in front. Antennae black, eye-caps silvery white. 

 Thorax black with slight brassy reflections. 



Fore wings black, with reddish metallic reflections when 

 viewed obliquely. At the basal fifth of the wing there is a 

 brilliant silvery fascia, becoming decidedly broader as it nears 

 the dorsum which it reaches at about the inner angle ; some- 

 times it broadens so considerably as almost to reach the base 

 of the wing. At the middle of the wing is a second fascia, in 

 some specimens almost wedge-shaped, with its base resting on 

 the dorsum. At the extreme apex of the wing is a silvery 

 patch of scales of variable extent ; in some cases it is merely 

 a rather large spot at the tornus ; in otliers it may extend from 

 the costa around the apex broadening toward the tornus ; in 

 a few specimens it is connected along the dorsum by a few 

 silvery scales with the second fascia. The color of these 

 fasciae varies considerably, depending on the direction of the 

 light, either silver or when viewed very obliquely, a metallic 

 pale blue. Cilia grayish black. Hind wings and cilia grayish 

 black. 



Legs black, fore and middle tarsi and last segment of the 

 hind tarsi ocherous. Abdomen blacjc above, sometimes silvery 

 beneath. 



Expanse : 4-4.3 mm. 



20 



