THE CANADIAN ENTOMOLOGIST. 75 



two small brownish spots on top of each of the next three segments after 

 the head, and is nearly cylindrical. It is exceedingly difficult to rear the 

 imago, mainly, I think, because the Osfrja leaves dry up so quickly, and 

 the larva will seldom make a new mine after leaving an old one, though I 

 have sometimes known it to do so. It leaves the mine to pupate in a 

 small whitish ovoid cocoon among the leaves on the ground. The mine 

 is a singular one. In the natural way it begins at the junction of a vein 

 and the midrib, and extends along the midrib to the next vein ; there the 

 parenchyma is taken out between the two veins and with the frass a little 

 tube is constructed along the midrib, and from the mouth of the tube to 

 the edge of the leaf two walls of frass are constructed, between which the 

 larva, when disturbed, retreats into its tube. In the breeding cage, when 

 the leaves are bent or the larva is crowded, it will sometimes vary the 

 form of its mine, or even form a new one, but I doubt if in a state of 

 nature it ever passes beyond the midrib or the two veins. From probably 

 three hundred mines which I have gathered, I have not succeeded in 

 raising half a dozen insects, and Dr. Clemens does not seem to have met 

 with better success, for he does not seem to have been acquainted with 

 the imago, though he mentions the mine and larva in his letter to Mr. 

 Stainton of Oct. loth, 1859, which is published with an excellent figure 

 of the mined leaf in Mr. Stainton's edition of the Clemens Papers, page 

 27. 



THE I so A, gC/L IIOV. 



]\Iaxillary palpi microscopic ; labial palpi ascending above the vertex 

 (a little longer than in Elachistd). Antennae simple, more than half as 

 long as the wings. Head and face smooth. 



Primaries lanceolate ovate ; the costal attains the margin just before 

 the middle. Discal cell very narrow, and closed by a very short discal 

 nervule ; the subcostal sends a branch to the margin from before the 

 middle, another from near the end of the cell, and then is deflexed to 

 meet the discal vein, beyond which it sends another branch to the costal 

 margin and there becomes furcate before the tip, delivering a short branch 

 to each margin near the tip. The discal vein is short, straight, a little 

 oblique, and without branches. The nriedian vein gives off to the dorsal 

 margin a single branch beyond the middle, and becomes furcate just 

 bevond the end of the cell. The submedian is furcate at the base. 



Posterior wings linear lanceolate. The costa slightly excised from the 

 middle to the tip ; the costal vein is near the margin, which it attains at 



