14 THE entomologist's RECORD. 



The eggs of Cyclopides palaemon and C. sylvius and their 

 Thymeliciae affinities {u-ith tliree plates). 



By T. A. CHAPMAN, M.D., F.Z.S., F.E.S. 



It may be desirable to begin by saying that the important point of 

 this note is the observation of the Thymelicine affinities of the eggs of 

 Ci/clopides, i.e., that they have not a circular, but an oval, horizontal 

 outline. Mr. Gillmer sent me four eggs of C. palaemon and three of 

 C. ailvim, so that the observation is not of an odd Qgg. On examining 

 these eggs, I soon noted the oval outline of C. silvius, but that of 

 C. palae.)tion escaped me, as it appears to have done previous observers, 

 until, by applying accurate measurements, I found it was little less 

 oval than that of C. silvius. After that I was able to see it under a 

 handlens. The photograph of theegg of C. palaemon ( x 20)in Tutt's Nat. 

 Hist, of Brit. Lepidoptera, vol. viii., p. 83, pi. i., fig. 6, shows, in 

 measurement, a long diameter of 17mm., a short one of 15mm., a 

 little more than the -Omm. to -Smm. I record, but really the same if 

 one admits a trifling vagueness in the outline in the plate. 



On June 15th, 1907, I received from Mr. M. Gillmer eggs of these 

 two species, with a request that I would describe them, as he con- 

 sidered the accepted descriptions were decidedly faulty. The texture 

 of the surface of the egg he especially notes as having been erroneously 

 reported. I have pleasure in doing my best to meet Herr Gillmer's 

 request, as the eggs have unquestionably many points of interest, and 

 as regards that of C. palaemon, the descriptions in Tutt's Nat. Hist. 

 Brit. Lep., vol. viii. {Brit. Butts., i.), p. 201, where we may assume all 

 that is known of it has been reported, are, to say the least, so defective as 

 to require supplementing. As there is no finality in such matters, it 

 may not be long before these notes will be found insufficient. Mr. 

 Gillmer says the eggs were laid on June 11th or 12th. The butterflies 

 were caught near Stralsund, in Pomerania, and sent to him alive, and 

 the eggs having been laid whilst the imagines were in his possession, 

 he can answer for the eggs being certainly those of the species named. 

 The eggs of the two species are much alike in size, form, and 

 colour ; in colour I see no difference, both being creamy -tinted, nearly 

 white ; in form they differ a little, but it is desirable first to describe 

 what the form is. They both have the oval outline of Thymelicine 

 eggs. This form of Qgg Avas first noted by Hellins (Buckler's Larvae, 

 vol. i., p. 196), though its peculiar significance was not then understood. 

 Mr. Tutt especially notes it in Nat. Hist. Brit. Butts. (1906), p. 91. 

 On this same page is a footnote quoted from me, which is certainly 

 obscure, if not misleading, and I may, by the way, take this oppor- 

 tunity of pointing out what I wished to explain. The micropyle is a 

 fixed and definite point of the egg, we may take it as a starting-point, 

 identical in all eggs. The great mass of lepidopterous eggs divide into 

 two sections. — (1) The more primitive, in which the egg is laid on its side 

 ("flat" eggs), with the micropyle at one end ; these eggs, seen from 

 above, are usually oval, and have, in fact, three unequal axes. (2) The 

 more evolved ("upright") is laid on the nadir of the micropyle, and 

 has the micropyle on top. In these the outline, seen from above, is 

 almost invariably circular. Certain Geometrids show how a " flat " 

 egg, in different members of a group, may acquire an upright position 

 and a circular outline in transverse section. The egg has, in fact, 

 except in the most primitive spherical eggs, a strong tendency to have 



