70 THK entomologist's KECORl). 



litUe. The dorsal ridge ends where the cremaster begins. The cre- 

 master, seen from above, is shaped much like a duck's beak, hollowed 

 out down the centre in the shape of an inverted V. Surface shiny, 

 but pitted. Colour, pale grey. The extremity is furnished with a 

 number of light brown, shiny hooks, shaped like a T, or more still, 

 like an anchor upside down. P. brussicao and P. rapae have similar 

 hooks. The spiracles are elongated ovals, with a very light brown or 

 yellowish central slit. They are just below the lateral ridge. The 

 pupa, when extimined under a low power (x 40), has a shiny, rather 

 waxy, appearance, though much pitted, and in some parts wrinkled. 

 The general colour is a very pale grey, slightly greenish on the 

 appendage-cases, less so on the wing-cases. In spotting, shape, and 

 colouring it is considerably like / '. hrassirat' on a small scale, resembling 

 this species more than it does P. rapae. 



Differential points in larvae and pup^e of P. manni and P. rap.e. — 

 The following arn the mam points of difference between P. vionni 

 and /'. rapae in the larval and pupal states. [I may have missed 

 some differences in the early stages of the larva), for I had no micro- 

 scope with me at the beginning of my observations.] I could see very 

 little difference in the Eggs. That of /'. rapae is a very little shorter 

 and proportionately stouter, measuring l*3mm. x "Smm. P. maniii 

 l-45mm. x •omin. The hand lens showed no difference of struc- 

 ture, colour or appearance in general. The Larva of P. manni has a 

 head more or less black for the first three instars, the first stage head 

 being almost entirely black. P. rapae has a pale yellow head to begin 

 with, becoming yellowish-green subsequently, and not quite green 

 until the 4th stage has been reached, it is never black. The body is 

 also paler in young P. rapae, which is no doubt partly owing to the 

 fact that the black points or tubercles are on a smaller scale. It is 

 of a pale green in the 3rd stage, and the dorsal and spiracular lines 

 are, as yet, barely visible, and are of a whitish-green, not yet distinctly 

 yellow, whereas, ni iiianni, the dorsal line is already distinguishable 

 towards the end of the 1st instar, being more strongl}' marked with 

 yellow in the 2nd instar, and showing distinctly, as is also the 

 spiracular line in the 3rd instar. The two species are probably more 

 alike in the 4th stage than in any other. P. iiianui has now a green 

 head and the body colour is much of the same green as in /'. rapae, 

 but, by the greater width of its dorsal and spiracular lines, and the 

 greater size of the black points sprinkled over the body and head 

 giving the larva a coarser and darker appearance, it is still quite easy 

 to recognise /'. manui. The same differences exist in the 5th stage 

 and are even more accentuated, so that there is never any difficulty in 

 separating the larvje. /'. rapae is of a tender green colour ; P. manni 

 bluish above and on sides, green beneath. (The autumn larvfe seem 

 to be bluer than those of the summer broods.) Dorsal line nearly 

 twice as wide in manni as in rapae. The lateral (spiracular) line is 

 also much wider and the spaces, separating the spots of which it is com- 

 posed, are not so wide. The larva has a rougher, coarser look than that 

 of P. rapae owing to the large size of many of the black tubercles and 

 the coarser hair they bear. /'. rapae appears soft and downy in com- 

 parison with manni. When preparing to pupate, iiianni develops a 

 tinge of purple on dorsum and sides, which I have not noticed in 



