&8 Phillips— Oxford Fossils. 



the posterior. If, with this in view, we compare it to the ordinary 

 Idbellula depressa, we shall find agreement; for in that insect the 

 hind wings are only three times as long as wide, and are broadest 

 near the body, but the front wings are four times as long as wide, 

 and are broadest near the middle. 



On the front edge, about two-thirds of the length of the -wing from 

 its origin, appeared what resembled the "stigma;" such, at least, at 

 first it appeared to me to be, but this position is much farther from 

 the tip than is usual in living Libellulidce ; though it agrees with that 

 assigned to the stigma in Aeshna liassica, by Professor Westwood, 

 in plate x. fig. 4, of Brodie's Fossil Insects. Upon clearing away 

 a small piece of the enveloping stone, I found it was certainly 

 formed by the approximate marginal costcs, and not the stigma, whose 

 true place was at s in fig. b. (See Plate VI.) 



The general plan of the principal veins and the intervening cells 

 can be understood by inspection of the drawing ; but for the sake of 

 comparison with other specimens it may be well to call attention to 

 two points. The smaller veins which branch out from the posterior 

 large vein, and proceed towards the margin, constitute a series of 

 nearly parallel and nearly equidistant nervures, somewhat irregularly 

 connected by less conspicuous threads in different directions. This 

 is not a common feature in the wings of living Libellulidcs ; but may 

 be traced in some fossils, as in plate viii. fig. 1, of Brodie's Fossil 

 Insects, which represents a smaller specimen from the Upper Lias 

 i^Aeshia Brodicei, Morris). The analogy which thus appears between 

 that Liassic and our Oolitic specimen, is confirmed by a comparison 

 of the principal veins ; for these take very similar directions and 

 separate spaces much in the same proportions, and, as far as appears, 

 filled by cells in a similar way. The second peculiarity worthy of 

 notice is in the arrangement of the main veins about the triangular 

 area which is so marked a feature in the wings of Libellididce. 



In Plate YI., fig. c, this arrangement is sketched from the Stones- 

 field Fossil, and in fig. d the same parts are seen enlarged from 

 Mr. Brodie's work, plate viii. fig. 1, which represents the Lias fossil. 



Reference may now be made to the important paper on Fossil 

 Insects, by Professor Westwood, in the tenth volume of the Quar- 

 terly Journal of the Gleological Society, and especially to the figure 

 of a Libellida from Eyeford, in Stonesfield Slate, part of the un- 

 rivalled collection of the Rev. P. B. Brodie, F.Gr.S. (plate xvii. 

 fig. 20). A pair of wings is here seen, "apparently the anterior," 

 as Professor Westwood remarks ; but the state of the specimen did 

 not permit of any examination of the anal angle of the wings, or the 

 precise form of the cells. Regarding them as anterior wings, they 

 appear to me decidedly allied to the fossil of which I give the 

 posterior wing ; and as the author of the excellent paper referred to 

 deserves, more, perhaps, than any other man of our country, the 

 thanks of Palgeontologists for his labour on fossil insects, let us call 

 this species, now in some respects clearly illustrated, lAbellula 

 Westwoodii. 



One who knows the value of the Stonesfield fauna in questions of 



