. Bulletin of the British Museum (Natural History), Geology. LOWER JURASSIC INSECTS OF DORSET 121 Holotype. ; Flatstones, Stonebarrow, Charmouth, Dorset; part and counterpart. Jackson colln. Dimensions: length (incomplete) 39mm, estimated wing length 50-52mm. Discussion. The holotype has been prepared by degagement, uncovering more of the fossil by removal of overlying rock. This has revealed more details than were available to Zeuner (1962), who identified this specimen as L. magnified Tillyard. Comparison of the newly-revealed basal part of the wing with the type of L. magnified
. Bulletin of the British Museum (Natural History), Geology. LOWER JURASSIC INSECTS OF DORSET 121 Holotype. ; Flatstones, Stonebarrow, Charmouth, Dorset; part and counterpart. Jackson colln. Dimensions: length (incomplete) 39mm, estimated wing length 50-52mm. Discussion. The holotype has been prepared by degagement, uncovering more of the fossil by removal of overlying rock. This has revealed more details than were available to Zeuner (1962), who identified this specimen as L. magnified Tillyard. Comparison of the newly-revealed basal part of the wing with the type of L. magnified shows that, apart from some differences in cell shapes, L. pseudomdgnificd is also substantially smaller. In L. magnifica the node, at 35-4 mm from the base, is almost equidistant from the tip of the wing. In the incomplete wing of L. pseudomdgnificd, on the other hand, the node is 25 mm from the base of the wing: if the two wings had similar proportions, this would mean a total wing length of 50 mm for L. pseudo- magnifica. The wingspan of L. magnifica was about 140 mm, whereas that of L. pseudomagnifica was only 100 mm. The possibility that L. pseudomagnifica was the (smaller) male of L. magnifica was considered. Variation in wing length in the Recent Anisozygoptera was discussed by Asahina (1954), who showed that a maximum variation within one species was 4 mm in the male and 3 mm in the female, well below the difference between L. magnifica and pseudomdgnificd; they are clearly not individual variants of one species. The number of cells in the cubital and anal areas, the shape of the discoidal cell and the reduction in number of antenodals separate L. pseudomdgnificd from Recent species of Epiophlebia, while the fossil species, L. jacksoni, is much smaller. Specimen was also incorrectly identified as L. mdgnificd by Zeuner (1962: 162); it may well be pseudomdgnificd but no further development has been possible. Liassophlebia jacksoni Zeuner, 1962 Fig. 6 1962 Liass
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