1196 THE BUTTERFLIES OF NEW ENGLAND. 



absence of those comparatively large, conical wartlets, ten or twelve times 

 larger than the smaller ones, which form so conspicuous a feature in both 

 P. napi and P. rapae, and which are arranged at subequidistant intervals 

 in a transverse row on each of the subsegments of the body ; they are 

 present in P. oleracea, but are not nearly so large relatively as in P. napi, 

 except possibly on the stigmatal subsections of the anterior part of the 

 body, and are further inconspicuous in being either concolorous with the 

 body, or white, or only a little infuscated, while in both the other species 

 mentioned they are piceous and most conspicuous ; occasionally, however, 

 when white, they are marked with a fuscous annulus around the base and 

 so are made more conspicuous, but herein they approach the normal type 

 of P. rapae and not of P. napi. 



The chrysalis of P. oleracea differs from that of P. napi of Europe, first, 

 in the following structural features : the frontal tubercle curves distinctly 

 upward, as shown in pi. 84, fig. -^7, while that of P. napi is directed 

 straight forward ; the elevation of the suprastigmatal carina to a distinct, 

 spinous, compressed tubercle on the sides of the anterior part of the third 

 abdominal segment, is far more marked, and the tubei'cle itself distinctly 

 flares laterally, which that of P. napi cannot be said to do. Second, in 

 colorational peculiarities : Chrysalids of P. napi are far more heavily 

 marked ; especially the suprastigmatal carina is margined interiorly with 

 large, blackish fuscous patches, forming a more or less interrupted band 

 over the second to the eighth abdominal segments ; the fourth to the tenth 

 segments have a distinct, mediodorsal black dash at the anterior margin ; 

 and the disk of the wing cases is marked with a double black dash besides 

 the black specks ; none of these markings are present in P. oleracea, ex- 

 cept the first named, on the second and third segments, and occasionally a 

 fuscous indication posterior to that ; the black specks or dots are found on 

 the wing cases, but the black dashes are wanting. The further dorsal 

 markings of the abdomen of P. napi consist, on most of the segments, of 

 a curving or diverging series of black dots, three on a side next the middle 

 line above, open posteriorly, and an oblique arrangement of two black dots 

 on either side, nearer the suprastigmatal than the mediodorsal carina, the 

 anterior marginal or submarginal and the outer, the other anterocentral 

 and the inner ; none of these except the submarginal dot of the outer series 

 is found at all in P. oleracea, and then only, as a general rule, on the 

 third to the sixth segments, and accompanied on the fifth and sixth by a 

 companion dot, sometimes double, a little way above the spiracle. 



The male imago of P. oleracea diflfers structurally from that of P. napi 

 in the hook of the upper organ of the abdominal appendages, which is 

 shorter and more strongly curved at tip, while the semicorneous expansion 

 of the under edges of the base is not a downward directed, vertical lamina, 

 thickening into a posterior, downward directed thorn, but a short curved 

 hook, opposed to the hook of the upper organ. 



