THE CANADIAN ENTOMOLOGIST. 229 



of a cylindrical sack, slightly bulbous at the extremity, and in length 

 equals or exceeds the thoracic feet. Just what function it may fulfil is at 

 present uncertain. 



For brevity in treating the following species, the application of these 

 points on larval structure is implied ; the variations from the usual form 

 will alone be noted. 



I have lately had the pleasure of examining the allied European 

 micacea and Ochria fiavago in various stages of their larval existence. 

 The former is a counterpart of our immajiis, and shows some typical de- 

 partures from the larvae here considered. Flavago is very near in general 

 appearance to cataphracta, and the larval similarity is closer still. That 

 the clypeal structure of the moth should differ so much seems odd, and 

 may be due to the borer not displaying sufficient instinct to make an exit 

 aperture, so that the moth must necessarily develop a clypeal spur to 

 pierce its way out through the epidermis of the food-plant in some such 

 manner as do the similarly armed Nonagria. It will be a matter of some 

 interest when our Gortyna (Ochria) Buffaloensis is again located, and its 

 history worked out so that comparisons may be made here. 



If Hydrmcia are so given to acquiring peculiarities due to special 

 wants or differing environments, it becomes evident the more light we 

 can throw on their full histories the better we shall be able to ultimately 

 associate them. 



The following early histories do not appear to be published : 



Hydicecin marginidens, Gn. 



Late in June this species was found boring in Cicuta viaculata, the 

 first specimen noted being high up in the plant, three feet or more above 

 ground. Its discovery happened through a little of that detective work 

 one learns in this branch, and which adds such a charm to the labour that 

 might otherwise seem rather arduous. For it is with clues and not the 

 culprits we have first to deal, and as these creatures are concealed at all 

 times, it is no easy matter locating them. A suspiciously broken twig or 

 withering stem, a knotty swelling, or a ventilating aperture, is usually 

 the evidence we have to work upon ; hence the satisfaction when a well- 

 directed search, prompted by some slight symptom, discloses an 

 Hydroecia. Attention was drawn to the Cicuta through a few inches of 

 the top having fallen down to one side, hanging black and withered. The 

 larva had worked upward so far that the diameter of the stem was wholly 



