354 Proceedings of the Royal Physical Society. 



The pupa measures 2f inches long, by 2% inches in its 

 greatest circumference, about the middle of its length. 



In the beginning of last October a box reached Dr S. 

 containing a small-sized pupa, and the cast skin of a cater- 

 pillar of the Death's-head Moth, along with some dry leaves 

 of the potato plant. A note from Mr D. M'Diarmid, Bridge- 

 end of Alness, Boss-shire, dated 8th September 1855, in- 

 formed Dr S. he had that day sent him " a live specimen of 

 natural history unknown to every one there, even to the 

 oldest inhabitant ; — it was a very large species of caterpillar 

 found among the potato plots of the village, and no less than 

 four specimens of it had been observed." Mr M'Diarmid 

 placed the caterpillar, along with some leaves for its food, 

 in a box, and sent it to Dr Smith, to see if he could learn 

 what the rare insect was. Unfortunately, the box did not 

 reach Dr Smith until more than a month afterwards, and he 

 found, instead of the caterpillar, the pupa (now exhibited) ; 

 the poor half-starved larva having apparently become pre- 

 maturely changed into the pupa state. It is therefore 

 very much less in size than the one previously described, 

 measuring only If inch long, by If inch in its greatest 

 circumference, about the middle of its length. It remained 

 alive for some time afterwards, but at last also died, without 

 changing into the imago or perfect insect, — an event which 

 seems very frequently to occur where the pupa is not kept 

 in its natural state, deeply buried in the damp earth. 



There is no doubt, from the smooth and regularly oval 

 pupa, as well as from the skin of the caterpillar, cast off at 

 its change into the pupa state — which displays, at the extre- 

 mity of its body, the characteristic deflexed and tubercular 

 horn, with its tip turned upwards — that this is also a pupa 

 of the Death's-head Moth. 



The two specimens of pupae now exhibited are curious, 

 as showing such a difference of size in the pupse of the same 

 insect. 



Another specimen of the Death's-head Moth, the perfect 

 insect, was sent to Dr Smith by the Eev. John Donaldson, 

 it was found lying dead last September at Druimchastel farm, 

 near Kin loch Eannoch, Perthshire. 



