25 



M3 leaves it proximad, i.e., about four cells' length. The sector- 

 lying between M2 and M3 indeterminate, apparently arising just 

 distad from M3 and supported bj^ strong cross-veins placed very 

 obliquely on either side of it, below the level of the nodus. Presence 

 or absence of bridge and oblique vein indeterminate, owing to 

 obliteration of venation in the region where the latter should be 

 looked for. M4 very irregular distally, breaking up into a zigzag 

 row of cell-borders. Space between M4 and Cu very wide, but 

 filled by only a single row of elongate cells bounded by parallel 

 cross-veins. Cu reaches the wing border at a level more than half- 

 way between nodus and pterostigma. 



TYPE : Mesophlebia antinodalis, sp. nov. 



OBS. : It is difficult to indicate any affinities between this 

 extraordinary wing and that of any other Odonate, fossil or recent. 

 The obviously very great breadth of the wing in proportion to its 

 length, and the close approximation of the nodus to the pterostigma, 

 make it almost certain that the wing is the hindwing of an Anisop- 

 terous dragon-fly. On the other hand the absence from the fragment 

 of the very important basal half of the wing, and the obliteration 

 (apparently by partial decomposition of overlying vegetable remains) 

 of just that small portion of the series of cross-veins between M 2 and 

 M3 where we should expect to find the oblique vein, makes the 

 definite determination of the sub-order to which it belongs an im- 

 possibility. It is not inconceivable that a Zygopterous hindwing of 

 the type shown in Epiophlebia might not have possessed a quad- 

 rilateral wide enough to allow of the development of a single row of 

 cells between M 4 and Cu, as elongate as those here shown. Pending 

 the discovery of further remains of this interesting insect, which we 

 may reasonably hope will be found if the Ipswich beds are more 

 fully worked, the genus has been placed in a new sub-family, Meso- 

 phlebiinse, characterised by the form of the nodus, and placed 

 provisionally as an isolated side-branch of the sub-order Anisoptera. 



MESOPHLEBIA ANTINODALIS, sp. nov. 

 Plate 4, fig. 2. 



The fragment 3 consists of the greater portion of the distal 

 half of the wing, from a point on the radius about six cells proximad 

 from the nodus, to a point just short of the wing-tip. A fracture 

 roughly perpendicular to the distal ending of M3, and hence parallel 

 to the direction of the nodus, has destroyed the extreme distal portion 

 of the wing-border. Vegetable remains overlie the wing in several 

 places, and have caused obliterations of some important cross-veins. 



