unusual monstrous Insects. 221 



"Butterflies of Great Britain, 1855," pi. vii. fig. 1. It 

 was captured by Mr. Doubleday at Epping, and is now 

 in the British Museum. The supplemental wing is here, 

 as in the former specimen affixed at the base of the 

 costal portion of the right hind wing, but here it is im- 

 planted on the upper side of the wing, and consequently 

 hides the outer costal and postcostal portion of the true 

 wing when seen from above; whereas in G. Rhamni, it is 

 affixed on the under surface of the wing, and is therefore 

 partially hidden by the costal portion of the true wing 

 when seen fi.-om above. The supplemental wing is here 

 much less developed than in the former case as shown in 

 figure '2b, where the costal vein a is not fully developed, 

 the subcostal vein h is destitute of its branch, the discoidal 

 vein is entirely wanting, but the median vein has its three 

 branches, d^, d" and d^, the last two, however, being 

 united together previous to arriving at the hind margin of 

 the wing, where in the true wing the most prominent point 

 of the margin is produced. 



The third specimen here represented (PI. VI. fig. 3) is 

 a male Hlpparcliia Janira, taken last year near Oxford, 

 and now in the Plopeian Entomological Museum. On the 

 upper side there is no apparent monstrosity, the uniform 

 brown colour of the wings not alloAving any irregularity 

 to be observed. On the underside the case is different, as 

 we here perceive on the left-hand hind wing an orange 

 streak with a moderately-large eyelet let in between the 

 subcostal and median portions of the wing, of which there 

 is no trace in the right-hand hind wing, and on carefully 

 examining the veins it is found that there is one vein 

 which does not normally exist as shown in fig. 3 a (the 

 abnormal) and 36, the normal wing ; moreover, it is upon 

 this extra vein and its neighbourhood that the fidvous 

 colour and the extra eyelet is found ; and as in no varieties 

 of the male of this species are the hind wings orange 

 coloured, Ave are led to the inevitable conclusion that this 

 left-hand hind wing has been supplemented by that precise 

 portion of an additional fore-wing which bears the discoidal 

 veins and the large eyelet near the tip of the normal fore- 

 wings. 



B. Insects with imperfectly-developed Heads. 



The other cases of insect monstrosity which I propose 

 to bring before the notice of the Society are those in 

 which the perfect insect retains some portion of the outer 



11 2 



