108 THE CANADIAN ENTOMOLOGIST. 



Besides the fern borer, marginidens and a stray cataphracta are all that 

 appear, and, disconsolate, it is feared our trip has been taken in vain. 

 The flora is but slightly different from that of Rye, and those plants 

 favourable for boring which are new to us are so few as to be easily 

 examined, but all give negative results. One of the number is such a 

 nice, smooth-skinned, stocky perennial, that it seems it should be infested 

 by something, if only a common nitela. So it is hardly a surprise when 

 in another locality, that has apparently run to waste for years, this plant is 

 found containing young Hydroecia at work in the stem. Not seeming 

 familiar, though at such an early stage one cannot be very positive, a score 

 or more are sought, and together with a supply of the food-plant are trans- 

 ported to the home menagerie. In due season a series of the imago is 

 at hand, and, strangely, it proves a species that will fit in nowhere. So, 

 though missing speciosissima, an unexpected result is scored in another 

 direction, and the Rhode Island venture is voted a success after all. The 

 succeeding year another lot of the larvae are secured, that our earlier 

 conclusions may be fully verified the second time, with a result to only 

 strengthen the former impressions. 



Upon encountering new forms in a genus already well represented, 

 and where these exhibit affinities closely connecting the representative 

 species, the questions of varietal limitation at once become important. 

 Perhaps the greatest help in such cases is a knowledge of larval develop- 

 ments, the wider the better, or the experience gained in viewing large 

 series of the imagoes as they emerge into the perfect state. So it will 

 happen in an extended study of Hydrxcia that certain delineations of 

 specific characters become more or less easy and offer lines by which we 

 may reasonably expect to differentiate them. More especially may this 

 hold when recognizable differences occur in the early stages as well, so 

 that it appears just how much one known valid species is separated from 

 its ally. With the importance now properly given to larval structure, and 

 especially that of tubercle arrangement as an aid in classification, the 

 theories arising as to the development, use and significance of these char- 

 acters are of more than passing interest. Furthermore, when considering 

 them as a means of graduating genera to our conceptions of what may be 

 " higher " or " lower " in point of specialization or descent, positive notes 

 as to the acquisition of these characters carry importance. Thus, when 

 meeting a Hydrxcia larva which nicely illustrated a point in this line, 

 there was naturally a desire to draw attention to it. Yet, try as we may, 



