284 THE ENTOMOLOGIST. 



July 23rd till August 8th last and saw only two males. Another 

 collector I met reported one, and Mr. H. A. Leeds, who spent nine 

 days there in mid-August, met with another. These four males, as 

 far as I am aware, are the only four native-born corydon seen there 

 this year. Not only the " syngrajyJia " ground but also the " all- 

 type " ground some little way off has suffered a like fate. Here, 

 where the species in '17 and '18 simply swarmed, this year I saw 

 under thirty specimens, six being females. Mr. Spiller reports the 

 butterfly very scarce in the Oxon Chilterns, whilst on the Hertford- 

 shire side Mr. L. Goodson, of Tring, says it has been quite abundant, 

 but with no special variety beyond semi-syngraj^ha. From Eoyston, 

 where I went on August 9th, I sent Mr. Leeds over 500 live females 

 with a sprinkling of a few males. These he very kindly put out on 

 the old syvgrapha ground in the hope that they would mate with any 

 possible straggler of the local race, and so, perhaps, eventually 

 re-establish tlie colony, or shall I put it a colony, as the re-entrance 

 of syngrapha appears to be very remote. The disappearance of 

 A. corydon, I think, is due to two main causes. Firstly, parasites : 

 In 1917 corydon was fairly plentiful, though not swarming (I am 

 alluding now to the syngraplia colony). In 1918 its numbers 

 had lessened by half, one portion of the ground being quite blank. 

 1919 saw the butterfly absolutely scarce. I gathered seventy larvae 

 in that July which produced six butterflies only, the remainder, with 

 the exception of a few diseased larva3, being stung. Some few threw 

 out dipterous grubs when full-fed, but the majority pupated and 

 from the pupae emerged a species of Hymenoptera. Secondly, 

 disease : I believe it is generally agreed that variation, excepting 

 striation, is due to disease or weakness, also thafgynandromorphism 

 denotes degeneration. I dori't think there was ever a colony of 

 A. corydon which produced more varieties per thousand specimens 

 than did the syngraplia strain ! One day in August last year I saw 

 less than fifty corydon out of which three were varieties, one 

 syngrapha and two obsoleta (one whitish, and one of the complete 

 form with merely faint traces of the lunules). Mr. H. Rowland- 

 Brown reported (' Entom.,' vol. 1, p. 236) the finding of one var. 

 syngraplia at another locality some miles from its regular ground. 

 In 1917 and the following year I put out a fair number of the 

 variety on another ground which his description fits, but personally 

 did not see any result from it. The species was scarce there last 

 year as in other parts, but I did not visit the place this year so 

 cannot say how it has fared. — G. B. Oliver ; Stocksbridge, Sep- 

 tember, 1920. 



Chrysophanus phl^as ab. c^ruleo-punctata. — Mr. Jacobs' 

 note {antea, p. 233) indicates that the blue-spot form of C. phlceas is 

 a native of marshy places. On September 18th of this year I took 

 six specimens at Quarndon (near Derby) on a patch of dry heathy 

 ground, where was also an abundance of gorse and thistles. Of these 

 butterflies four were of the blue-spot form. The following Saturday 

 I took six more, and of these five were blue-spotted forms. I also 

 captured a large number on some very marshy ground near Duflield, 

 but none of these bore any trace of the blue marking, nor, indeed, 



