522 Scientific Proceedings, Royal Dublin Society. 



larva. The antennae are conspicuous, and the mouth-parts not different 

 from those occurring in older larvae. The prothorax and pronotal shield 

 are large, the latter not well chitinised, and with a distinct suture along the 

 nrid-dorsal line. It carries the normal number of bristles. The different 

 plates of the mesothorax and metathorax are distinct ; the two minute 

 anterior alar bristles are not discernible; otherwise the arrangement is similar 

 to that obtaining in old larvae. Epipleural lobes of abdomen not prominent ; 

 body cuticle, generally soft in the first eight segments of the abdomen, and 

 bristle-plates indistinct. Normal number of bristles doi'sally in prescutal, 

 scutal, and scutellar series. The minute anterior alar bristle missing, and 

 also the anterior-dorsal pleural bristle. Ninth abdominal segment large and 

 well chitinised, and carries the normal number of bristles; they are larger 

 than those on the other segments, especially the posterior ventral pair ; these 

 project conspicuously, and have their tips curved inwards. 



{d) Second-stage Larva (PI. XVI, figs. 10 and 11). — Length, 2'0 to 3'0 mm. 

 Form very narrowly elongate, with the epipleural lobes projecting very con- 

 spicuously. Head, 0-19 mm. broad across epicranium. Segments of abdomen 

 with well-defined prescutum, scutum, and scutellum. Arrangement of 

 bristles as in final-stage larva. Bristle-plates distinct before the moult, and 

 distantly separated owing to the expansion of the cuticle during growth. 

 Ninth abdominal segment- bristles not longer than those on the other 

 segments. Anal-proleg long. 



(e) The Pupa (PL XIX). — Average length, 1-4 mm. ; colour, creamy white ; 

 cuticle soft throughout, and easily crushed. The general form is short and 

 stout, with the knees of the hind-legs projecting conspicuously at the sides, as 

 is common in flea-beetle pupae generally. The head is bent underneath the 

 thorax, by which it is obscured from dorsal view, while the posterior part of 

 the abdomen is also bent ventral wards, and carries a pair of prominent 

 curved and chitinised hooks. The developing mouth-parts are seen in week- 

 old specimens. Antennae folded around the dorsal surfaces of the first and 

 second pairs of legs quite near the knee-joints, and extend posteriorly and 

 medianly to form graceful loops ; their sheaths are provided with many 

 prominent blunt processes, a circular series being present on the portion 

 corresponding to each segment of the antenna. In young pupae the eyes of 

 the developing adult are not distinct, but in older specimens they appear as 

 large, dark-coloured areas, and a strong bristle arises from the pupal cuticle 

 just above each. Besides these, the head is provided with another pair of 

 strong bristles on the cranial region, which are supported on elevations of 

 the pupal cuticle, while a further pair of smaller bristles occurs on the frons 

 region. When viewed from the dorsal surface, the prothorax appears rounded 



