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Hewitsoniamim. Both species are included by Dr. Giebel in his 

 list. On the subject of these supposed remains of Lepidoptera 

 Mr. Scudder observes : " I have not been able to find, even with 

 Mr. Brodie's help, the first specimens referred to ; but an 

 examination of the original of the latter proved that while it is 

 unquestionably an insect it cannot be referred to the Lepidoptera. 

 As the figure of the first species clearly resembles, in this 

 particular, the one I have seen, I am forced to the conclusion 

 that neither of these wings are Lepidopterous. Plainly, the only 

 reason why a new generic name was appended to these forms, was 

 that their remains were too fragmentary to afford the slightest 

 guess as to what modern genus they might be referred." All 

 geologists are, of course, aware that the formation known as the 

 " Purbeck Beds " occurs not only in the peninsula of Purbeck in 

 Dorsetshire, but also in some parts of Wiltshire and Buckingham- 

 shire, and elsewhere. This formation in the vale of Wardour in 

 Wiltshire, consists, according to Mr. P. B. Brodie, of a series of 

 clays, white limestones, grits, sandstones, coarse blue limestones, 

 and fine white slaty limestones. In this last-mentioned limestone, 

 insect remains have been detected in such abundande, that it has 

 been called, both here and in Dorsetshire, the " Insect Limestone." 

 It is described as being of a somewhat coarse texture, often white 

 at the edges, and of a blue colour towards the centre, where it 

 becomes fine grained and harder, and then joins into a thin white 

 slaty limestone, very fine grained and having a laminated structure. 

 It was chiefly from these strata in the vale of Wardour in Wilts, 

 and the vale of Aylesbury in Bucks, that the large collections of 

 fossil insects were obtained which furnished materials for Brodie's 

 "History of the Fossil Insects in the Secondary Eocks of 

 England," before referred to. Out of some two hundred and 

 forty specimens, or parts of specimens, from these formations,, 

 seventy-four * were figured by Professor Westwood in the work 

 last mentioned. The very fragmentary and imperfect condition 



* Introductory observations to Brodie's "Fossil Insects," by Professor 

 J. 0. Westwood, M.A, F;L.S., &c. 



