282 THE CANADIAN ENTOMOLOGIST. 



The thoracic tufcing of this species from its smaller size seems more 

 prominent than in some others. Indeed, this character so noticeable 

 throughout the group can only be fully appreciated by securing moths 

 direct from pupae and which have not marred their beauty here by flight. 

 The rather loose, though ample, vesiture of the thorax is so well blended 

 with certain ground colours of the primaries, together with minor 

 peculiarities of the anterior tufts, that it is quite possible to separate the 

 species by the thorax alone when unfaded, perfect material is at hand. 

 This may seem a rather broad statement, yet it is the lack of perfect 

 material that has resulted until recently in the confusion of certain 

 species. 



Mr. Grote, when conducting his studies in the earlier days, gives 

 a figure (Papilio, pi. i. Vol. II.) showing a profile view of rigida that 

 illustrates nicely the proportions of this tufting. 



Hydroecia Harris ii, Grt. 



A number of mature larv* of this species came into my possession 

 last season, due to the kindness of Dr. Roland Thaxter, who has long had 

 this insect under observation at Kittery Point, Maine. That section so 

 far seems the only one which has produced this species in numbers ; the 

 examples in collections invariably bear that locality label. As its food- 

 plant and early history have already been discussed by my donor who 

 furnished the types for the original description, the references here will 

 have only to deal with some of the tubercle arrangements which are 

 of interest by way of comparison, for there were some suspicions at the 

 start that it might prove a vdsxoX.^ oi purpurifascia. So great was the 

 similarity between these larvae and the one found working in Cicuta — both, 

 in fact, being UmbeUiferx feeders— that it was thought possible the local 

 and the Maine examples might be the same until emergence proved the 

 contrary. Since, comparisons of blown larvae have pointed out sufficient 

 structural diff'erences ; but a slightly greater size in favour of marginidetis 

 seemed at first the only apparent discrepancy. 



Mature larva : General dimensions are typical, colour the light 

 indistinct translucence. A dorsal stripe is vaguely seen, apparently 

 dependent on the pulsating internal fluids for accentuation. Head 

 measures .11 inch across ; shield and anal plate ordinary. Tubercles are 



