106 PAPERS BY DR. B. CLEMENS. 



The larva mines the leaves of Crataegus tomentosa early 

 in September. The mine appears at first as a very narrow 

 line, and is subsequently expanded into a small, transparent 

 blotch. At maturity the larva weaves a cocoon between the 

 cuticles, and cuts out a small oval disk. This is sometimes 

 carried quite a distance, and is ultimately secured to some 

 object by one of its ends tied down on a little button of white 

 silk. It enters the pupa state toward the latter part of 

 September, and appears as an imago in early spring. 



The mature larva has a head much smaller than the first 

 ring, rounded above, and elliptical. The body is flattened, 

 and tapers posteriorly from the anterior rings. The seg- 

 ments are rather deeply incised, the thoracic obtusely rounded 

 at the sides, and the rest with a minute lateral nodule or 

 mammilla. It is Avithout legs or prolegs, but on the second 

 and third thoracic rings, on both the dorsal and ventral sur- 

 faces, are spots or cup-like depressions, one on each side, 

 capable of being contracted and expanded. So, likewise, 

 from the sixth to the ninth inclusive, on the ventral surface 

 are transversely placed oval spots, similar to the thoracic, 

 and one on each segment. On the segment next the last is 

 a protuberance, both dorsal and ventral, with two cup-like 

 depressions on each surface. These are not supplied with 

 hooks, and, if they are substitutes for feet, must act like 

 suckers. They are all pale brown. The head is dark brown ; 

 the body brown, with blackish along the dorsal and ventral 

 surfaces. 



When the larvas are young, it is extremely difficult to 

 discover their mines, and the transparent blotch is not much 

 larger than the cocoon, leaving a space in which the " frass" 

 is collected. 



DlACHORISIA. 



Fore-wings pointed, narrowly ovate-lanceolate ; discoidal 

 cell closed behind by a very faintly indicated nervure, with a 

 faintly indicated secondary cell. The subcostal nervure ob- 

 scurely indicated from the secondary cell to the base of the 



