146 Mr. J. W. Dunning on 



form of the wing-scales ; and Nolcken says that the shape 

 of the scales, as figured by Kolenati, is not true to nature. 

 Speyer points out that Westwood (In trod. ii. 324) ex- 

 pressly denies the existence of the inner spine or appen- 

 dage to the fore-tibiae which he observed in A. Nevce, and 

 adds, '^ Since all my specimens show it, this circumstance 

 is only explicable to me by the supposition, that the 

 English species is not identical with that of the Neva. 

 Westwood's other characters, as well as Stainton's short 

 description, certainly as to the rest agree very well 

 with Russian examples.'^ But surely where the spurs 

 on the mid- and hind-tibise have been looked for 

 in vain by so many observers (including Speyer him- 

 self, at the time he penned the sentence I have 

 quoted), it is too much to. say that, because West- 

 wood's specimen did not exhibit this minute appen- 

 dage to the fore-tibiae, therefore A. Nevce must be a 

 different species from his. Be it remembered, too, that 

 out of all the specimens from the Neva, nobody but 

 Speyer has ever been able to detect this object; though 

 told what to look for, I cannot find it on any English 

 specimen ; but it seems far more likely that this appen- 

 dage, like the other leg-appendages, is deciduous and 

 easily lost, than that there should be two species, alike in 

 everything else, down to the minutest particular, but 

 distinguished, one by the possession, and the other by 

 the absence, of this spine. In truth, this difference, if 

 it really existed, would be something more than a specific 

 difference, it would be a generic distinction. And the 

 same remark applies to the ocelli ; Nolcken mentions 

 the ocelli of Nevce as if their presence would serve to 

 distinguish it from the English species, apparently for- 

 getting that both Curtis and Stephens say " ocelli two," 

 so that there is, at least, as much evidence in favour of 

 their existence in Garnonsii and Hansoni as in Nevce ; at 

 the same time, Nolcken doubts the existence of any 

 ocelli in Nevce, and considers that Kolenati was in error. 

 But again I say, this difference, if it really existed, would 

 be a generic, not a specific distinction ; and, for myself, 

 I cannot doubt, that if one Acentrojncs has ocelli, they all 

 have. In 1864, after an abstract from the Natural His- 

 tory of Tutbury, Newman (Zool. 8920) said, 'Hhe species 

 A. Nevce, distinguished by the broad velvet-umber belt 

 round the abdomen, is the one most commonly seen in 

 cabinets ; the beautiful belt has been mistaken for grease 



