66 THE CANADIAN ENTOMOLOGIST. 



Body is slender, of the usual cylindrical build, the constrictions of the 

 thoracic regions are already noted. Colour as in earlier stage, a pale 

 sienna, in some specimens showing rather pink on the first four abdomi- 

 nal joints. This area is not crossed by the longitudinal lines. These 

 latter are whitish ; on the thoracic segments they are rather confused, 

 their continuation on the rear abdominal ones shows well-defined and 

 regular. Thoracic shield a little wider than the head, of the same 

 shining, corneous texture, edged faintly at the sides with brown ; anal 

 plate is similar, smooth and shining, its setae of usual prominence. The 

 tubercles are all well defined, of an umber shade, iv the largest of the 

 lateral ones. On joints two and three, iii, iv and v are clustered in their 

 triangular setting, and by reason of their large size, especially iv, almost 

 touch one another. On all segments but the next to last, i and ii are 

 small, as is customary, and show somewhat darker. On joint eleven 

 these are very large and placed in quadrangular form. The plates 

 preceding the anal one are barely cut in twain by a thread of the dorsal 

 line. The spiracle on joint one is most conspicuous by reason of the 

 lighter colour of this segment, and it is entirely black. The other 

 spiracles show a light centre and have their elliptical margin ringed with 

 black. On the seventh abdominal segment there are five tubercles 

 clustered around the spiracle. What had previously been considered as 

 a raising of iv, in some cases, to the upper corner of the spiracle, seems 

 now very plainly the acquisition of an accessory tubercle at this point, the 

 normal iv all the while retaining its usual position on this segment, lower 

 down. But this additional one is as fully developed as iv is on this or the 

 preceding joints, and its placing corresponds identically with the arrange- 

 ment as occurring on joints four to eight. With two other species this 

 additional tubercle first appears in this penultimate stage, iv previously 

 occupying its lower position and remaining unchanged after entering the 

 stage, the additional tubercle now appearing, but causes no alteration 

 with the normal iv. We may designate this acquisition as iv a, looking 

 upon its arrival in the same light as the other cases cited, though 

 observations with limpida were insufficient to say at what time it was 

 acquired. Larva now measures 1.38 inches. 



Final stage : There appears no structural change from the preceding 

 period. The lines disappear, a flesh-coloured translucence is now the 

 tint. The spiracles, tubercles and true-legs are all black ; the shields ar e 

 unchanged. Length 1.63 inches. Larvae attain full growth by August 19. 



